Light-emitting device and electronic apparatus including the same

ABSTRACT

A light-emitting device includes a first electrode, a second electrode facing the first electrode, and an interlayer between the first electrode and the second electrode. The interlayer includes an emission layer. The interlayer further includes a first electron transport layer and a second electron transport layer. The first and second electron transport layers are between the emission layer and the second electrode. The first electron transport layer includes a first compound represented by Formula 1, and the second electron transport layer includes a second compound represented by Formula 2.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2020-0158051, filed Nov. 23, 2021, which is hereby incorporated by reference for all purposes as if fully set forth herein.

BACKGROUND Field

One or more embodiments generally relate to a light-emitting device and an electronic apparatus including the light-emitting device.

DISCUSSION

Among light-emitting devices, self-emissive devices have wide viewing angles, excellent contrast, short response times, excellent brightness, admirable driving voltages, and exceptional response speed characteristics.

In typical a light-emitting device, a first electrode is located on a substrate, and a hole transport region, an emission layer, an electron transport region, and a second electrode are sequentially formed on the first electrode. Holes provided from the first electrode may move toward the emission layer through the hole transport region, and electrons provided from the second electrode may move toward the emission layer through the electron transport region. In this manner, carriers, such as holes and electrons, recombine in the emission layer to produce excitons, which transition from an excited state to a ground state to thereby generate light.

The above information disclosed in this section is only for understanding the background of the inventive concepts, and, therefore, may contain information that does not form prior art.

SUMMARY

One or more embodiments provide a light-emitting device including a first electron transport layer, which includes a first compound, and a second electron transport layer, which includes a second compound, such that the light-emitting device is capable of having high heat resistance, low driving voltage, high efficiency, and long lifespan.

One or more embodiment provide an electronic apparatus including a light-emitting device, which includes a first electron transport layer, which includes a first compound, and a second electron transport layer, which includes a second compound, such that the light-emitting device is capable of having high heat resistance, low driving voltage, high efficiency, and long lifespan.

Additional aspects will be set forth in the detailed description which follows, and, in part, will be apparent from the disclosure, or may be learned by practice of the inventive concepts.

According to one or more embodiments, a light-emitting device includes: a first electrode; a second electrode facing the first electrode; and an interlayer between the first electrode and the second electrode, the interlayer including an emission layer. The interlayer further includes a first electron transport layer and a second electron transport layer. The first and second electron transport layers are between the emission layer and the second electrode. The first electron transport layer includes a first compound represented by Formula 1, and the second electron transport layer comprises a second compound represented by Formula 2.

Formula 1 is:

Formula 2 is:

In Formula 1 and Formula 2: two of X₁₁ to X₁₃ are N, and the remaining one of X₁₁ to X₁₃ is C(R₁₅); X₂₁ to X₂₆ are each independently C(R₂₁) or N, at least one of X₂₁ to X₂₃ and at least one of X₂₄ to X₂₆ is N; CY₁₁ and CY₁₂ are each independently a C₃-C₆₀ carbocyclic group; CY₂₁ is a naphthylene group unsubstituted or substituted with at least one R₂₂ or a fluorenylene group unsubstituted or substituted with at least one R₂₂; L₁₁ to L₁₃, L₂₁, and L₂₂ are each independently a single bond, a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a), or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a); a11 to a13, a21, and a22 are each independently an integer from 1 to 5; Ar₁₁, Ar₁₂, and Ar₂₁ to Ar₂₄ are each independently a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a); b11 and b12 are each independently an integer from 1 to 5; R₁₁ to R₁₅, R₂₁, and R₂₂ are each independently hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group unsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkenyl group unsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkynyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ alkoxy group unsubstituted or substituted with at least one R_(10a), a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ aryloxy group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ arylthio group unsubstituted or substituted with at least one R_(10a), —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), or —P(═O)(Q₁)(Q₂); c11 is an integer from 1 to 3; c12 is an integer from 1 to 4; two neighboring groups of R₁ in the number of c11, two neighboring groups of R₁₂ in the number of c12, R₁₃, R₁₄, or any combination thereof, are optionally linked to each other and form a cyclic group unsubstituted or substituted with at least one R_(10a); R_(10a) is: deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or a nitro group; C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, or a C₁-C₆₀ alkoxy group, each unsubstituted or substituted with at least one of deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂); a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, or a C₆-C₆₀ arylthio group, each unsubstituted or substituted with at least one of deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂); or —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), or —P(═O)(Q₃₁)(Q₃₂). Further, Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ are each independently: hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; a C₁-C₆₀ alkyl group; a C₂-C₆₀ alkenyl group; a C₂-C₆₀ alkynyl group; a C₁-C₆₀ alkoxy group; or a C₃-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group, each unsubstituted or substituted with at least one of deuterium, —F, a cyano group, a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkoxy group, a phenyl group, a biphenyl group.

According to one or more embodiments, an electronic apparatus includes a light-emitting device. The light-emitting device includes: a first electrode; a second electrode facing the first electrode; and an interlayer between the first electrode and the second electrode, the interlayer including an emission layer. The interlayer further includes a first electron transport layer and a second electron transport layer. The first and second electron transport layers are between the emission layer and the second electrode. The first electron transport layer includes a first compound represented by Formula 1, and the second electron transport layer comprises a second compound represented by Formula 2.

Formula 1 is:

Formula 2 is:

In Formula 1 and Formula 2: two of X₁₁ to X₁₃ are N, and the remaining one of X₁₁ to X₁₃ is C(R₁₅); X₂₁ to X₂₆ are each independently C(R₂₁) or N, at least one of X₂₁ to X₂₃ and at least one of X₂₄ to X₂₆ is N; CY₁₁ and CY₁₂ are each independently a C₃-C₆₀ carbocyclic group; CY₂₁ is a naphthylene group unsubstituted or substituted with at least one R₂₂ or a fluorenylene group unsubstituted or substituted with at least one R₂₂; L₁₁ to L₁₃, L₂₁, and L₂₂ are each independently a single bond, a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a), or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a); a11 to a13, a21, and a22 are each independently an integer from 1 to 5; Ar₁₁, Ar₁₂, and Ar₂₁ to Ar₂₄ are each independently a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a); b11 and b12 are each independently an integer from 1 to 5; R₁₁ to R₁₅, R₂₁, and R₂₂ are each independently hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group unsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkenyl group unsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkynyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ alkoxy group unsubstituted or substituted with at least one R_(10a), a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ aryloxy group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ arylthio group unsubstituted or substituted with at least one R_(10a); —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), or —P(═O)(Q₁)(Q₂); c11 is an integer from 1 to 3; c12 is an integer from 1 to 4; two neighboring groups of R₁₁ in the number of c11, two neighboring groups of R₁₂ in the number of c12, R₁₃, R₁₄, or any combination thereof, are optionally linked to each other and form a cyclic group unsubstituted or substituted with at least one R_(10a); R_(10a) is: deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or a nitro group; C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, or a C₁-C₆₀ alkoxy group each, independently, unsubstituted or substituted with at least one of deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₂), —B(Q₁₁)(Q₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₂); a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, or a C₆-C₆₀ arylthio group each, independently, unsubstituted or substituted with at least one of deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂); or

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), or —P(═O)(Q₃₁)(Q₃₂). Further, Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ are each independently: hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; a C₁-C₆₀ alkyl group; a C₂-C₆₀ alkenyl group; a C₂-C₆₀ alkynyl group; a C₁-C₆₀ alkoxy group; a C₃-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group each, independently, unsubstituted or substituted with at least one of deuterium, —F, a cyano group, a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkoxy group, a phenyl group, and a biphenyl group.

The foregoing general description and the following detailed description are illustrative and explanatory and are intended to provide further explanation of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the inventive concepts, and are incorporated in and constitute a part of this specification, illustrate embodiments of the inventive concepts, and, together with the description, serve to explain principles of the inventive concepts. In the drawings:

FIG. 1 is a schematic cross-sectional view of a light-emitting device according to an embodiment; and

FIGS. 2 and 3 are schematic cross-sectional views of an electronic apparatus according to various embodiments.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of various embodiments. As used herein, the terms “embodiments” and “implementations” may be used interchangeably and are non-limiting examples employing one or more of the inventive concepts disclosed herein. It is apparent, however, that various embodiments may be practiced without these specific details or with one or more equivalent arrangements. In other instances, well-known structures and devices are shown in block diagram form to avoid unnecessarily obscuring various embodiments. Further, various embodiments may be different, but do not have to be exclusive. For example, specific shapes, configurations, and characteristics of an embodiment may be used or implemented in another embodiment without departing from the inventive concepts.

Unless otherwise specified, the illustrated embodiments are to be understood as providing example features of varying detail of some embodiments. Therefore, unless otherwise specified, the features, components, modules, layers, films, panels, regions, aspects, etc. (hereinafter individually or collectively referred to as an “element” or “elements”), of the various illustrations may be otherwise combined, separated, interchanged, and/or rearranged without departing from the inventive concepts.

The use of cross-hatching and/or shading in the accompanying drawings is generally provided to clarify boundaries between adjacent elements. As such, neither the presence nor the absence of cross-hatching or shading conveys or indicates any preference or requirement for particular materials, material properties, dimensions, proportions, commonalities between illustrated elements, and/or any other characteristic, attribute, property, etc., of the elements, unless specified. Further, in the accompanying drawings, the size and relative sizes of elements may be exaggerated for clarity and/or descriptive purposes. As such, the sizes and relative sizes of the respective elements are not necessarily limited to the sizes and relative sizes shown in the drawings. When an embodiment may be implemented differently, a specific process order may be performed differently from the described order. For example, two consecutively described processes may be performed substantially at the same time or performed in an order opposite to the described order. Also, like reference numerals denote like elements.

When an element, such as a layer, is referred to as being “on,” “connected to,” or “coupled to” another element, it may be directly on, connected to, or coupled to the other element or intervening elements may be present. When, however, an element is referred to as being “directly on,” “directly connected to,” or “directly coupled to” another element, there are no intervening elements present. Other terms and/or phrases used to describe a relationship between elements should be interpreted in a like fashion, e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” “on” versus “directly on,” etc. Further, the term “connected” may refer to physical, electrical, and/or fluid connection. For the purposes of this disclosure, “at least one of X, Y, and Z” and “at least one selected from the group consisting of X, Y, and Z” may be construed as X only, Y only, Z only, or any combination of two or more of X, Y, and Z, such as, for instance, XYZ, XYY, YZ, and ZZ. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

Although the terms “first,” “second,” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used to distinguish one element from another element. Thus, a first element discussed below could be termed a second element without departing from the teachings of the disclosure. Further, the term “interlayer” as used herein refers to a single layer and/or all layers between a first electrode and a second electrode of a light-emitting device. Moreover, the expression “(an interlayer and/or a capping layer) includes at least one heterocyclic compound represented by Formula 1” as used herein may include a case in which “(an interlayer and/or a capping layer) includes identical compounds represented by Formula 1” and a case in which “(an interlayer and/or a capping layer) includes two or more different compounds represented by Formula 1.”

Spatially relative terms, such as “beneath,” “below,” “under,” “lower,” “above,” “upper,” “over,” “higher,” “side” (e.g., as in “sidewall”), and the like, may be used herein for descriptive purposes, and, thereby, to describe one element's relationship to another element(s) as illustrated in the drawings. Spatially relative terms are intended to encompass different orientations of an apparatus in use, operation, and/or manufacture in addition to the orientation depicted in the drawings. For example, if the apparatus in the drawings is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the term “below” can encompass both an orientation of above and below. Furthermore, the apparatus may be otherwise oriented (e.g., rotated 90 degrees or at other orientations), and, as such, the spatially relative descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing some embodiments and is not intended to be limiting. As used herein, the singular forms, “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Moreover, the terms “comprises,” “comprising,” “includes,” and/or “including,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components, and/or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It is also noted that, as used herein, the terms “substantially,” “about,” and other similar terms, are used as terms of approximation and not as terms of degree, and, as such, are utilized to account for inherent deviations in measured, calculated, and/or provided values that would be recognized by one of ordinary skill in the art.

Various embodiments are described herein with reference to sectional views, isometric views, perspective views, plan views, and/or exploded illustrations that are schematic illustrations of idealized embodiments and/or intermediate structures. As such, variations from the shapes of the illustrations as a result of, for example, manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments disclosed herein should not be construed as limited to the particular illustrated shapes of regions, but are to include deviations in shapes that result from, for instance, manufacturing. To this end, regions illustrated in the drawings may be schematic in nature and shapes of these regions may not reflect the actual shapes of regions of a device, and, as such, are not intended to be limiting.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure is a part. Terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense, unless expressly so defined herein.

Hereinafter, various embodiments will be explained in detail with reference to the accompanying drawings.

FIG. 1 is a schematic cross-sectional view of a light-emitting device 10 according to an embodiment.

The light-emitting device 10 may include a first electrode 110, an interlayer 130, and a second electrode 150. Hereinafter, the structure of the light-emitting device 10 according to an embodiment and a method of manufacturing the light-emitting device 10 will be described in connection with FIG. 1.

First Electrode 110

In FIG. 1, a substrate may be additionally located under the first electrode 110 or above the second electrode 150. The substrate may be a glass substrate or a plastic substrate. In an embodiment, the substrate may be a flexible substrate, and may include plastics with excellent heat resistance and durability, such as at least one of polyimide, polyethylene terephthalate (PET), polycarbonate, polyethylene naphthalate, polyarylate (PAR), and polyetherimide.

The first electrode 110 may be formed by, for example, depositing or sputtering a material for forming the first electrode 110 on the substrate. When the first electrode 110 is an anode, a material for forming the first electrode 110 may be a high work function material that facilitates injection of holes.

The first electrode 110 may be a reflective electrode, a semi-transmissive electrode, or a transmissive electrode. When the first electrode 110 is a transmissive electrode, a material for forming the first electrode 110 may include at least one of indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO2), and zinc oxide (ZnO). In an embodiment, when the first electrode 110 is a semi-transmissive electrode or a reflective electrode, at least one of magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), and magnesium-silver (Mg—Ag) may be used as a material for forming the first electrode 110.

The first electrode 110 may have a single layer consisting of a single-layered structure or a multilayer structure including a plurality of layers. For example, the first electrode 110 may have a three-layered structure of ITO/Ag/ITO.

Interlayer 130

The interlayer 130 may be located on the first electrode 110. The interlayer 130 may include a hole transport region having an emission layer and located between the first electrode 110 and the emission layer, and an electron transport region located between the emission layer and the second electrode 150.

The interlayer 130 may further include metal-containing compound, such as at least one of organometallic compounds, inorganic materials (e.g., quantum dots, etc.), and the like, in addition to various organic materials.

In an embodiment, the interlayer 130 may include: i) two or more emitting units sequentially stacked between the first electrode 110 and the second electrode 150; and ii) a charge generation layer located between the two emitting units. When the interlayer 130 includes the emitting unit and the charge generation layer as described above, the light-emitting device 10 may be a tandem light-emitting device.

First Electron Transport Layer and Second Electron Transport Layer

The interlayer 130 may include a first electron transport layer and second electron transport layer. The first and second electron transport layers may be located between the emission layer and the second electrode 150.

The first electron transport layer may include a first compound represented by Formula 1, and the second electron transport layer may include a second compound represented by Formula 2:

In Formula 1, two of X₁₁ to X₁₃ may be N, and the remaining one of X₁₁ to X₁₃ may be C(R₁₅).

For example, in Formula 1:

X₁₁ and X₁₂ may be N, and X₁₃ may be C(R₁₅),

X₁₁ and X₁₃ may be N, and X₁₂ may be C(R₁₅); or

X₁₂ and X₁₃ may be N, and X₁₁ may be C(R₁₅).

In Formula 2, X₂₁ to X₂₆ may each independently be C(R₂₁) or N, and at least one of X₂₁ to X₂₃ and at least one of X₂₄ to X₂₆ may be N.

In an embodiment, each of X₂₁ to X₂₆ in Formula 2 may be N.

In Formula 1, CY₁₁ and CY₁₂ may each independently be a C₃-C₆₀ carbocyclic group.

In an embodiment, CY₁₁ and CY₁₂ may each independently be a benzene group, a naphthalene group, a phenanthrene group, an anthracene group, or a pyrene group.

For example, CY₁₁ and CY₁₂ may each independently be a benzene group or a naphthalene group.

In an embodiment, a group represented by

in Formula 1 may be a group represented by one of Formulae 1A-1 to 1A-5:

In Formulae 1A-1 to 1A-5:

R_(10aa) and R_(10ab) may be each independently be the same as described in connection with R_(10a);

c12′ may be 1 or 2;

c13 may be an integer from 1 to 4;

R₁₁ to R₁₄, c11, c12, and R_(10a) may be the same as described herein; and

* indicates a binding site to a neighboring atom.

In Formula 2, CY₂₁ may be a naphthylene group unsubstituted or substituted with at least one R₂₂ or a fluorenylene group unsubstituted or substituted with at least one R₂₂. R₂₂ is the same as described herein.

The fluorenylene group used herein may include a fluorenylene group having a spiro structure.

In an embodiment, CY₂₁ in Formula 2 may be a group represented by one of Formulae 2A-1 to 2A-15:

In Formulae 2A-1 to 2A-5:

Y₂₁ may be O or S;

R_(22a), R_(22b), R_(22c), and R_(22d) may each independently be the same as described in connection with R₂₂, R_(22c), and R_(22d), and may be optionally linked to each other via a single bond, a C₁-C₅ alkylene group, a C₂-C₅ alkenylene group, O, or S to form a cyclic group unsubstituted or substituted with at least one R_(10a);

b21 may be an integer from 1 to 6;

b22 may be an integer from 1 to 3;

b23 may be an integer from 1 to 4;

R₂₂ may be the same as described herein; and

* and *′ each indicate a binding site to a neighboring atom.

In an embodiment, CY₂₁ in Formula 2 may be a group represented by one of Formulae 2AA-1 to 2AA-22:

In Formulae 2AA-1 to 2AA-22:

“Ph” refers to a phenyl group; and

* and *′ each indicate a binding site to a neighboring atom.

In Formulae 1 and 2, L₁₁ to L₁₃, L₂₁, and L₂₂ may each independently be a single bond, a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a), or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a).

In an embodiment, L₁₁ to L₁₃, L₂₁, and L₂₂ may each independently be:

a single bond; or

a benzene group, a pentalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthylene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, or an imidazopyrimidine group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C1-C20 alkyl group, a C1-C20 alkoxy group, a phenyl group, a pentalenyl group, an indenyl group, a naphthalenyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an ace naphthalenyl group, a fluorenyl group, a spiro-bifluorenyl group, a spiro-benzofluorene-fluorenyl group, a benzofluorenyl group, a dibenzo fluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a carbazolyl group, a benzosilolyl group, a dibenzosilolyl group, a quinolinyl group, an isoquinolinyl group, a benzimidazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂).

Q₃₁ to Q₃₃ may each independently be a C1-C10 alkyl group, a C1-C10 alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group.

In an embodiment, L₁₁ to L₁₃, L₂₁, and L₂₂ may each independently be a single bond or a group represented by one of Formulae 3-1 to 3-25:

In Formulae 3-1 to 3-25:

Y₁ may be O, S, C(Z₃)(Z₄), N(Z₅), or Si(Z₆)(Z₇);

Z₁ to Z₇ may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, a C1-C20 alkyl group, a C1-C20 alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a pyrenyl group, a chrysenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group, a carbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a triazinyl group, a benzimidazolyl group, a phenanthrolinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), or —B(Q₃₁)(Q₃₂);

Q₃₁ to Q₃₃ may each independently be a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group;

d3 may be an integer from 1 to 3;

d4 may be an integer from 1 to 4;

d5 may be an integer from 1 to 5;

d6 may be an integer from 1 to 6;

d8 may be an integer from 1 to 8; and

* and *′ each indicate a binding site to a neighboring atom.

In an embodiment, in Formula 1, L₁₃ may be a phenylene group unsubstituted or substituted with at least one R_(10a). For example, L₁₃ in Formula 1 may be a group represented by one of Formulae 3-1 to 3-3.

In an embodiment, the first compound may be a compound represented by Formula 1-1.

In Formula 1-1, X₁₁ to X₁₃, CY₁₁, CY₁₂, L₁₁, L₁₂, a11 to a13, Ar₁₁, Ar₁₂, b11, b12, R₁₁ to R₁₄, c11, and c12 are each the same as described herein.

In Formulae 1 and 2, a11 to a13, a21, and a22 may each independently be an integer from 1 to 5. When a11 is 2 or more, two or more of L11(s) may be identical to or different from each other. When a12 is 2 or more, two or more of L12(s) may be identical to or different from each other. When a13 is 2 or more, two or more of L13(s) may be identical to or different from each other. When a21 is 2 or more, two or more of L21(s) may be identical to or different from each other. When a22 is 2 or more, two or more of L22(s) may be identical to or different from each other.

In an embodiment, a11 to a13 in Formula 1 may each independently be 1, 2, or 3, and a21 and a22 in Formula 2 may each independently be 1 or 2, but embodiments are not limited thereto.

In Formulae 1 and 2, Ar₁₁, Ar₁₂, and Ar₂₁ to Ar₂₄ may each independently be a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a).

In an embodiment, Ar₁₁, Ar₁₂, and Ar₂₁ to Ar₂₄ may each independently be a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a spiro-cyclopentane-fluorenyl group, spiro-cyclohexane-fluorenyl group, a spiro-fluorene-benzofluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, an indolyl group, an isoindolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, a benzoisothiazolyl group, a benzoxazolyl group, a benzoisoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a thiadiazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, an azacarbazolyl group, a diaza carbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, an azadibenzosilolyl group, an imidazopyridinyl group or an imidazopyrimidinyl group, each unsubstituted or substituted with at least one of deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkyl group substituted with at least one phenyl group, a C₁-C₂₀ alkoxy group, a cyclohexenyl group, a phenyl group, a biphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a spiro-cyclopentane-fluorenyl group, a spiro-cyclohexane-fluorenyl group, a spiro-fluorene-benzofluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, an indolyl group, an isoindolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, a benzoisothiazolyl group, a benzoxazolyl group, a benzoisoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a thiadiazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, an azacarbazolyl group, a diaza carbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, an azadibenzosilolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂); and

Q₃₁ to Q₃₃ may each independently be a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group.

For example, Ar₁₁, Ar₁₂, and Ar₂₁ to Ar₂₄ may each independently be a phenyl group, a naphthyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, or a triazinyl group, each unsubstituted or substituted with at least one of deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, and a triazinyl group.

In an embodiment, Ar₁₁, Ar₁₂, and Ar₂₁ to Ar₂₄ may each independently be a group represented by one of Formulae 5-1 to 5-29:

In Formulae 5-1 to 5-29:

Y₃₁ may be O, S, N(Z₃₅), C(Z₃₃)(Z₃₄), or Si(Z₃₆)(Z₃₇);

Z₃₁ to Z₃₇ may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkyl group substituted with at least one phenyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a spiro-fluorene-benzofluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), or —B(Q₃₁)(Q₃₂),

e2 may be 1 or 2;

e3 may be an integer from 1 to 3;

e4 may be an integer from 1 to 4;

e5 may be an integer from 1 to 5;

e6 may be an integer from 1 to 6;

e7 may be an integer from 1 to 7; and

e9 may be an integer from 1 to 9.

It is noted that Q₃₁ to Q₃₃ may each independently be a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group.

In addition, * indicates a binding site to a neighboring atom.

In an embodiment, b11 and b12 in Formula 1 may each independently be an integer from 1 to 5.

For example, b11 and b12 may each independently be 1 or 2, but embodiments are not limited thereto.

In Formulae 1 and 2, R₁₁ to R₁₅, R₂₁, and R₂₂ may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group unsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkenyl group unsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkynyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ alkoxy group unsubstituted or substituted with at least one R_(10a), a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ aryloxy group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ arylthio group unsubstituted or substituted with at least one R_(10a), —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), or —P(═O)(Q₁)(Q₂);

c11 may be an integer from 1 to 3;

c12 may be an integer from 1 to 4; and

at least one of two neighboring groups of R₁₁ in the number of c11 and two neighboring groups of R₁₂ in the number of c12, R₁₃ and R₁₄ may be optionally linked to each other to form a cyclic group unsubstituted or substituted with at least one R_(10a).

In an embodiment, R₁₁ to R₁₅, R₂₁, and R₂₂ may each independently be:

hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or a nitro group;

C₁-C₂₀ alkyl group or a C₁-C₂₀ alkoxy group, each unsubstituted or substituted with at least one of deuterium, —F, —Cl, —Br, —I, a cyano group, a phenyl group, and a biphenyl group;

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a spiro-cyclopentane-fluorenyl group, spiro-cyclohexane-fluorenyl group, a spiro-fluorene-benzofluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, an indolyl group, an isoindolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, a benzoisothiazolyl group, a benzoxazolyl group, a benzoisoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a thiadiazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, an azacarbazolyl group, a diaza carbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, an azadibenzosilolyl group, an imidazopyridinyl group, or an imidazopyrimidinyl group, each unsubstituted or substituted with at least one of deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkyl group substituted with at least one phenyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a spiro-cyclopentane-fluorenyl group, spiro-cyclohexane-fluorenyl group, a spiro-fluorene-benzofluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, an indolyl group, an isoindolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, a benzoisothiazolyl group, a benzoxazolyl group, a benzoisoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a thiadiazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, an azacarbazolyl group, a diazacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, an azadibenzosilolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),

—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂); or

—Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), or —B(Q₁)(Q₂).

It is noted that Q₁₁ to Q₁₃, and Q₃₁ to Q₃₃ may each independently be a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group.

In an embodiment, the group represented by

and the group represented by

in Formula 2 may each independently be a group represented by one of the groups represented by 2B-1 to 2B-20:

In Formulae 2B-1 to 2B-20, * indicates a binding site to a neighboring atom.

In an embodiment, the group represented by

and the group represented by

in Formula 2 may be identical to each other.

For example, in Formula 2, the group represented by

and the group represented by

may each be represented by any one of Formulas 2B-1 to 2B-20, and may be identical to each other.

For example, the first compound may be one of the following compounds M-1-1 to M-1-30 and/or the second compound may be one of the following compounds M-2-1 to M-2-19, but embodiments are not limited thereto.

In an embodiment, the glass transition temperature (T_(g)) of the first compound may be about 110° C. to about 160° C., for example, about 120° C. to about 140° C., but embodiments are not limited thereto.

In conventional light-emitting devices, compounds having a low glass transition temperature have been used as electron transport materials, resulting in poor high-temperature heat resistance and rapid deterioration of efficiency when driving at a high temperature for a long time. Light-emitting devices according to some embodiments may include a compound having a high glass transition temperature as an electron transport material. The first compound represented by Formula 1 includes a pyrimidine ring as a ring containing X₁₁, X₁₂, and X₁₃ in Formula 1, and thus, has a high glass transition temperature. Accordingly, the first compound may have increased heat resistance to Joule (or resistive) heat and resistance under high temperature environments. Thus, light-emitting devices including the first compound have increased heat resistance and high durability during storage and driving conditions.

In a light-emitting device according to an embodiment, by using the second compound represented by Formula 2 as an electron transport material of the light-emitting device, electron mobility may be improved and electron injection into an emission layer may be improved. Accordingly, the light-emitting device may have a low driving voltage, high efficiency, and/or long lifespan characteristics.

Accordingly, by using the first compound and the second compound as an electron transport material for a light-emitting device, not only are high-temperature heat resistance and durability improved, but a light-emitting device also having low driving voltage, high efficiency, and/or long lifespan characteristics may be implemented.

In an embodiment, the first electron transport layer may be located between the emission layer and the second electron transport layer. In an embodiment, the second electron transport layer may be located between the emission layer and the first electron transport layer.

In an embodiment, the first electron transport layer and the second electron transport layer may directly contact each other. For example, the first electron transport layer and the second electron transport layer may be sequentially located from the emission layer, the emission layer and the first electron transport layer may directly contact each other, and the first electron transport layer and the second electron transport layer may directly contact each other.

In an embodiment, the thicknesses of the first electron transport layer and the second electron transport layer may each independently be from about 10 Å to about 1000 Å, for example, from about 50 Å to about 500 Å.

In an embodiment, at least one of the first electron transport layer and the second electron transport layer may further include a metal-containing material.

For example, the second electron transport layer may further include the metal-containing material. In this case, a weight ratio of the second compound to the metal-containing material may be about 1:9 to about 9:1.

The metal-containing material may include at least one of an alkali metal complex and an alkaline earth metal complex. The metal ion of an alkali metal complex may be a Li ion, a Na ion, a K ion, a Rb ion, or a Cs ion, and the metal ion of an alkaline earth metal complex may be a Be ion, a Mg ion, a Ca ion, a Sr ion, or a Ba ion. A ligand coordinated with the metal ion of the alkali metal complex or the alkaline earth-metal complex may include at least one of a hydroxyquinoline, a hydroxyisoquinoline, a hydroxybenzoquinoline, a hydroxyacridine, a hydroxyphenanthridine, a hydroxyphenyloxazole, a hydroxyphenylthiazole, a hydroxyphenyloxadiazole, a hydroxyphenylthiadiazole, a hydroxyphenylpyridine, a hydroxyphenylbenzimidazole, a hydroxyphenylbenzothiazole, a bipyridine, a phenanthroline, and a cyclopentadiene.

For example, the metal-containing material may include a Li complex. The Li complex may include, for example, Compound ET-D1 (LiQ) or ET-D2:

Hole Transport Region in Interlayer 130

The hole transport region may have: i) a single-layered structure consisting of a single layer consisting of a single material, ii) a single-layered structure consisting of a single layer consisting of a plurality of different materials, or iii) a multi-layered structure including a plurality of layers including different materials.

The hole transport region may include at least one of a hole injection layer, a hole transport layer, an emission auxiliary layer, and an electron blocking layer.

For example, the hole transport region may have a multi-layered structure including a hole injection layer/hole transport layer structure, a hole injection layer/hole transport layer/emission auxiliary layer structure, a hole injection layer/emission auxiliary layer structure, a hole transport layer/emission auxiliary layer structure, or a hole injection layer/hole transport layer/electron blocking layer structure. In each of these structures, the layers are stacked sequentially from the first electrode 110.

In an embodiment, the hole transport region may include a hole injection layer and a hole transport layer. The hole transport layer may include a first hole transport layer including a first hole transport material and a second hole transport layer including a second hole transporting material different from the first hole transport material.

The hole transport region may include at least one of a compound represented by Formula 201 and a compound represented by Formula 202:

In Formulae 201 and 202:

L₂₀₁ to L₂₀₄ may each independently be a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a);

L₂₀₅ may be *—O—*′, *—S—*′, *—N(Q₂₀₁)—*′, a C₁-C₂₀ alkylene group unsubstituted or substituted with at least one R_(10a), a C₂-C₂₀ alkenylene group unsubstituted or substituted with at least one R_(10a), a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a), or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a);

xa1 to xa4 may each independently an integer from 0 to 5;

xa5 may be an integer from 1 to 10;

R₂₀₁ to R₂₀₄, and Q₂₀₁ may each independently be a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a);

R₂₀₁ and R₂₀₂ may optionally be linked to each other, via a single bond, a C₁-C₅ alkylene group unsubstituted or substituted with at least one R_(10a), or a C₂-C₅ alkenylene group unsubstituted or substituted with at least one R_(10a), to form a C₈-C₆₀ polycyclic group (for example, a carbazole group or the like) unsubstituted or substituted with at least one R_(10a) (see Compound HT16 or the like);

R₂₀₃ and R₂₀₄ may optionally be linked to each other, via a single bond, a C₁-C₅ alkylene group unsubstituted or substituted with at least one R_(10a), or a C₂-C₅ alkenylene group unsubstituted or substituted with at least one R_(10a), to form a C₈-C₆₀ polycyclic group unsubstituted or substituted with at least one R_(10a); and

na1 may be an integer from 1 to 4.

In an embodiment, each of Formulae 201 and 202 may include at least one of groups represented by Formulae CY201 to CY217.

In Formulae CY201 to CY217, R_(10b) and R_(10c) are each the same as described in connection with R_(10a), and ring CY₂₀₁ to ring CY₂₀₄ may each independently be a C₃-C₂₀ carbocyclic group or a C₁-C₂₀ heterocyclic group, and at least one hydrogen in Formulae CY201 to CY217 may be unsubstituted or substituted with at least one R_(10a).

In an embodiment, ring CY₂₀₁ to ring CY₂₀₄ in Formulae CY201 to CY217 may each independently be a benzene group, a naphthalene group, a phenanthrene group, or an anthracene group.

In an embodiment, each of Formulae 201 and 202 may include at least one of groups represented by Formulae CY201 to CY203.

In an embodiment, Formula 201 may include at least one of groups represented by Formulae CY201 to CY203 and at least one of groups represented by Formulae CY204 to CY217.

In an embodiment, xa1 in Formula 201 may be 1, R₂₀₁ may be a group represented by one of Formulae CY201 to CY203, xa2 may be 0, and R₂₀₂ may be a group represented by one of Formulae CY204 to CY207.

In an embodiment, each of Formulae 201 and 202 may not include a group represented by one of Formulae CY201 to CY203.

In an embodiment, each of Formulae 201 and 202 may not include a group represented by one of Formulae CY201 to CY203, and may include at least one of the groups represented by Formulae CY204 to CY217.

In an embodiment, each of Formulae 201 and 202 may not include a group represented by one of Formulae CY201 to CY217.

In an embodiment, the hole transport region may include at least one of Compounds HT1 to HT46, m-MTDATA, TDATA, 2-TNATA, NPB(NPD), β-NPB, TPD, Spiro-TPD, Spiro-NPB, methylated-NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA), polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA), poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS), polyaniline/camphor sulfonic acid (PANI/CSA), and polyaniline/poly(4-styrenesulfonate) (PANI/PSS).

Compounds HT1 to HT46 are as follows:

A thickness of the hole transport region may be in a range of about 50 Å to about 10,000 Å, for example, about 100 Å to about 4,000 Å. When the hole transport region includes at least one of a hole injection layer and a hole transport layer, a thickness of the hole injection layer may be in a range of about 100 Å to about 9,000 Å, for example, about 100 Å to about 1,000 Å, and a thickness of the hole transport layer may be in a range of about 50 Å to about 2,000 Å, for example, about 100 Å to about 1,500 Å. When the thicknesses of the hole transport region, the hole injection layer, and the hole transport layer are within these ranges, satisfactory hole transporting characteristics may be obtained without a substantial increase in driving voltage.

The emission auxiliary layer may increase light emission efficiency by compensating for an optical resonance distance according to the wavelength of light emitted by an emission layer, and the electron blocking layer may block the leakage of electrons from an emission layer to a hole transport layer. Materials that may be included in the hole transport region as described above may be included in the emission auxiliary layer and the electron blocking layer.

P-Dopant

The hole transport region may further include, in addition to these materials, a charge-generation material for the improvement of conductive properties. The charge-generation material may be uniformly or non-uniformly dispersed in the hole transport region (for example, in the form of a single layer consisting of a charge-generation material).

The charge-generation material may be, for example, a p-dopant.

In an embodiment, the lowest unoccupied molecular orbital (LUMO) energy level of the p-dopant may be −3.5 eV or less.

In an embodiment, the p-dopant may include at least one of a quinone derivative, a cyano group-containing compound, and a compound containing element EL1 and element EL2.

Examples of the quinone derivative are TCNQ, F4-TCNQ, and the like.

Examples of the cyano group-containing compound are HAT-CN, and a compound represented by Formula 221 below.

In Formula 221:

R₂₂₁ to R₂₂₃ may each independently be a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a); and

at least one of R₂₂₁ to R₂₂₃ may each independently be a C₃-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group, each substituted with a cyano group; —F; —Cl; —Br; —I; a C₁-C₂₀ alkyl group substituted with a cyano group, —F, —Cl, —Br, —I, or any combination thereof, or any combination thereof.

In the compound containing element EL1 and element EL2, element EL1 may be at least one of a metal and a metalloid, and element EL2 may be at least one of a non-metal and a metalloid.

Examples of the metal are an alkali metal (for example, lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), etc.); an alkaline earth metal (for example, beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), etc.); a transition metal (for example, titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), technetium (Tc), rhenium (Re), iron (Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu), silver (Ag), gold (Au), etc.); a post-transition metal (for example, zinc (Zn), indium (In), tin (Sn), etc.); and a lanthanide metal (for example, lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), etc.).

Examples of the metalloid are silicon (Si), antimony (Sb), and tellurium (Te).

Examples of the non-metal are oxygen (O) and halogen (for example, F, Cl, Br, I, etc.).

In an embodiment, examples of the compound containing element EL1 and element EL2 are at least one of metal oxide, metal halide (for example, metal fluoride, metal chloride, metal bromide, or metal iodide), metalloid halide (for example, metalloid fluoride, metalloid chloride, metalloid bromide, or metalloid iodide), and metal telluride.

Examples of the metal oxide are tungsten oxide (for example, WO, W₂O₃, WO₂, WO₃, W₂O₅, etc.), vanadium oxide (for example, VO, V₂O₃, VO₂, V₂O₅, etc.), molybdenum oxide (MoO, Mo₂O₃, MoO₂, MoO₃, Mo₂O₅, etc.), and rhenium oxide (for example, ReO₃, etc.).

Examples of the metal halide are alkali metal halide, alkaline earth metal halide, transition metal halide, post-transition metal halide, and lanthanide metal halide.

Examples of the alkali metal halide are LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, and CsI.

Examples of the alkaline earth metal halide are BeF₂, MgF₂, CaF₂, SrF₂, BaF₂, BeCl₂, MgCl₂, CaCl₂, SrCl₂, BaCl₂, BeBr₂, MgBr₂, CaBr₂, SrBr₂, BaBr₂, BeI₂, MgI₂, CaI₂, SrI₂, and BaI₂.

Examples of the transition metal halide are titanium halide (for example, TiF₄, TiCl₄, TiBr₄, TiI₄, etc.), zirconium halide (for example, ZrF₄, ZrCl₄, ZrBr₄, ZrI₄, etc.), hafnium halide (for example, HfF₄, HfCl₄, HfBr₄, HfI₄, etc.), vanadium halide (for example, VF₃, VCl₃, VBr₃, VI₃, etc.), niobium halide (for example, NbF₃, NbCl₃, NbBr₃, NbI₃, etc.), tantalum halide (for example, TaF₃, TaCl₃, TaBr₃, TaI₃, etc.), chromium halide (for example, CrF₃, CrCl₃, CrBr₃, CrI₃, etc.), molybdenum halide (for example, MoF₃, MoCl₃, MoBr₃, MoI₃, etc.), tungsten halide (for example, WF₃, WCl₃, WBr₃, WI₃, etc.), manganese halide (for example, MnF₂, MnCl₂, MnBr₂, MnI₂, etc.), technetium halide (for example, TcF₂, TcCl₂, TcBr₂, TcI₂, etc.), rhenium halide (for example, ReF₂, ReCl₂, ReBr₂, ReI₂, etc.), iron halide (for example, FeF₂, FeCl₂, FeBr₂, FeI₂, etc.), ruthenium halide (for example, RuF₂, RuCl₂, RuBr₂, RuI₂, etc.), osmium halide (for example, OsF₂, OsCl₂, OsBr₂, OsI₂, etc.), cobalt halide (for example, CoF₂, CoCl₂, CoBr₂, CoI₂, etc.), rhodium halide (for example, RhF₂, RhCl₂, RhBr₂, RhI₂, etc.), iridium halide (for example, IrF₂, IrCl₂, IrBr₂, IrI₂, etc.), nickel halide (for example, NiF₂, NiCl₂, NiBr₂, NiI₂, etc.), palladium halide (for example, PdF₂, PdCl₂, PdBr₂, PdI₂, etc.), platinum halide (for example, PtF₂, PtCl₂, PtBr₂, PtI₂, etc.), copper halide (for example, CuF, CuCl, CuBr, CuI, etc.), silver halide (for example, AgF, AgCl, AgBr, AgI, etc.), and gold halide (for example, AuF, AuCl, AuBr, AuI, etc.).

Examples of the post-transition metal halide are zinc halide (for example, ZnF₂, ZnCl₂, ZnBr₂, ZnI₂, etc.), indium halide (for example, InI₃, etc.), and tin halide (for example, SnI₂, etc.).

Examples of the lanthanide metal halide are YbF, YbF₂, YbF₃, SmF₃, YbCl, YbCl₂, YbCl₃ SmCl₃, YbBr, YbBr₂, YbBr₃ SmBr₃, YbI, YbI₂, YbI₃, and SmI₃.

An example of the metalloid halide is antimony halide (for example, SbCl₅, etc.).

Examples of the metal telluride are alkali metal telluride (for example, Li₂Te, Na₂Te, K₂Te, Rb₂Te, Cs₂Te, etc.), alkaline earth metal telluride (for example, BeTe, MgTe, CaTe, SrTe, BaTe, etc.), transition metal telluride (for example, TiTe₂, ZrTe₂, HfTe₂, V₂Te₃, Nb₂Te₃, Ta₂Te₃, Cr₂Te₃, Mo₂Te₃, W₂Te₃, MnTe, TcTe, ReTe, FeTe, RuTe, OsTe, CoTe, RhTe, IrTe, NiTe, PdTe, PtTe, Cu₂Te, CuTe, Ag₂Te, AgTe, Au₂Te, etc.), post-transition metal telluride (for example, ZnTe, etc.), and lanthanide metal telluride (for example, LaTe, CeTe, PrTe, NdTe, PmTe, EuTe, GdTe, TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, LuTe, etc.).

Emission Layer in Interlayer 130

When the light-emitting device 10 is a full-color light-emitting device, the emission layer may be patterned into a red emission layer, a green emission layer, and/or a blue emission layer, according to a sub-pixel structure. In an embodiment, the emission layer may have a stacked structure of two or more layers of a red emission layer, a green emission layer, and a blue emission layer, in which the two or more layers contact each other or are separated from each other. In an embodiment, the emission layer may include two or more materials of a red light-emitting material, a green light-emitting material, and a blue light-emitting material, in which the two or more materials are mixed with each other in a single layer to emit white light.

The emission layer may include a host and a dopant. The dopant may include at least one of a phosphorescent dopant and a fluorescent dopant.

The amount of the dopant in the emission layer may be from about 0.01 to about 15 parts by weight based on 100 parts by weight of the host.

In an embodiment, the emission layer may include a quantum dot.

The emission layer may include a delayed fluorescence material. The delayed fluorescence material may act as a host or a dopant in the emission layer.

A thickness of the emission layer may be in a range of about 100 Å to about 1,000 Å, for example, about 200 Å to about 600 Å. When the thickness of the emission layer is within these ranges, excellent light-emission characteristics may be obtained without a substantial increase in driving voltage.

Host

In an embodiment, the host may include a compound represented by Formula 301 below:

[Ar₃₀₁]_(xb11)-[(L₃₀₁)_(xb1)-R₃₀₁]_(xb21)  Formula 301

In Formula 301:

Ar₃₀₁ and L₃₀₁ may each independently be a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a);

xb11 may be 1, 2, or 3;

xb1 may be an integer from 0 to 5;

R₃₀₁ may be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group unsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkenyl group unsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkynyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ alkoxy group unsubstituted or substituted with at least one R_(10a), a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a), —Si(Q₃₀₁)(Q₃₀₂)(Q₃₀₃), —N(Q₃₀₁)(Q₃₀₂), —B(Q₃₀₁)(Q₃₀₂), —C(═O)(Q₃₀₁), —S(═O)₂(Q₃₀₁), or —P(═O)(Q₃₀₁)(Q₃₀₂);

xb21 may be an integer from 1 to 5; and

Q₃₀₁ to Q₃₀₃ are the same as described in connection with Q₁.

For example, xb11 in Formula 301 is 2 or more, two or more of Ar₃₀₁(s) may be linked to each other via a single bond.

In an embodiment, the host may include a compound represented by at least one of Formula 301-1 and a compound represented by Formula 301-2.

In Formulae 301-1 to 301-2:

ring A₃₀₁ to ring A₃₀₄ may each independently be a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a);

X₃₀₁ may be O, S, N-[(L₃₀₄)_(xb4)-R₃₀₄], C(R₃₀₄)(R₃₀₅), or Si(R₃₀₄)(R₃₀₅);

xb22 and xb23 may each independently be 0, 1, or 2;

L₃₀₁, xb1, and R₃₀₁ are the same as described herein;

L₃₀₂ to L₃₀₄ may each independently be the same as described in connection with L₃₀₁;

xb2 to xb4 may each independently be the same as described in connection with xb1; and

R₃₀₂ to R₃₀₅ and R₃₁₁ to R₃₁₄ are the same as described in connection with R₃₀₁.

As another example, the host may include at least one of an alkaline earth metal complex and a post-transition metal complex. In an embodiment, the host may include at least one of a Be complex (for example, Compound H55), an Mg complex, and a Zn complex.

In an embodiment, the host may include at least one of Compounds H1 to H124, 9,10-di(2-naphthyl)anthracene (ADN), 2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN), 9,10-di-(2-naphthyl)-2-t-butyl-anthracene (TBADN), 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP), 1,3-di-9-carbazolylbenzene (mCP), and 1,3,5-tri(carbazol-9-yl)benzene (TCP), but embodiments are not limited thereto.

Compounds H1 to H124 are as follows:

Phosphorescent Dopant

In an embodiment, the phosphorescent dopant may include at least one transition metal as a central metal.

The phosphorescent dopant may include at least one of a monodentate ligand, a bidentate ligand, a tridentate ligand, a tetradentate ligand, a pentadentate ligand, and a hexadentate ligand.

The phosphorescent dopant may be electrically neutral.

For example, the phosphorescent dopant may include an organometallic compound represented by Formula 401:

In Formulae 401 and 402:

M may be transition metal (for example, iridium (Ir), platinum (Pt), palladium (Pd), osmium (Os), titanium (Ti), gold (Au)hafnium (Hf), europium (Eu), terbium (Tb), rhodium (Rh), rhenium (Re), or thulium (Tm));

L₄₀₁ may be a ligand represented by Formula 402, and xc1 may be 1, 2, or 3, and when xc1 is 2 or more, two or more of L₄₀₁(s) may be identical to or different from each other;

L₄₀₂ may be an organic ligand, and xc2 may be 0, 1, 2, 3, or 4, and when xc2 is 2 or more, two or more of L₄₀₂(s) may be identical to or different from each other;

X₄₀₁ and X₄₀₂ may each independently be nitrogen or carbon;

ring A₄₀₁ and ring A₄₀₂ may each independently be a C₃-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group;

T₄₀₁ may be a single bond, *—O—*′, *—S—*′, *—C(═O)—*′, *—N(Q₄₁₁)-*′, *—C(Q₄₁₁)(Q₄₁₂)-*′, *—C(Q₄₁₁)=C(Q₄₁₂)-*′, *—C(Q₄₁₁)=*′, or *═C═*′;

X₄₀₃ and X₄₀₄ may each independently be a chemical bond (for example, a covalent bond or a coordination bond), O, S, N(Q₄₁₃), B(Q₄₁₃), P(Q₄₁₃), C(Q₄₁₃)(Q₄₁₄), or Si(Q₄₁₃)(Q₄₁₄);

Q₄₁₁ to Q₄₁₄ are the same as described in connection with Q₁;

R₄₀₁ and R₄₀₂ may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₂₀ alkyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₂₀ alkoxy group unsubstituted or substituted with at least one R_(10a), a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a), —Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), —N(Q₄₀₁)(Q₄₀₂), —B(Q₄₀₁)(Q₄₀₂), —C(═O)(Q₄₀₁), —S(═O)₂(Q₄₀₁), or —P(═O)(Q₄₀₁)(Q₄₀₂);

Q₄₀₁ to Q₄₀₃ are the same as described in connection with Q₁;

xc11 and xc12 may each independently be an integer from 0 to 10; and

* and *′ in Formula 402 each indicate a binding site to M in Formula 401.

For example, in Formula 402, i) X₄₀₁ may be nitrogen, and X₄₀₂ may be carbon, or ii) each of X₄₀₁ and X₄₀₂ may be nitrogen.

In an embodiment, when xc1 in Formula 402 is 2 or more, two ring A₄₀₁ in two or more of L₄₀₁(s) may be optionally linked to each other via T₄₀₂, which is a linking group, and two ring A₄₀₂ may optionally be linked to each other via T₄₀₃, which is a linking group (see Compounds PD1 to PD4 and PD7). T₄₀₂ and T₄₀₃ are the same as described in connection with T₄₀₁.

L₄₀₂ in Formula 401 may be an organic ligand. For example, L₄₀₂ may include at least one of a halogen group, a diketone group (for example, an acetylacetonate group), a carboxylic acid group (for example, a picolinate group), —C(═O), an isonitrile group, —CN group, and a phosphorus group (for example, a phosphine group, a phosphite group, etc.).

The phosphorescent dopant may include, for example, at least one of compounds PD1 to PD25.

Compounds PD1 to PD25 are as follows:

Fluorescent Dopant

The fluorescent dopant may include at least one of an amine group-containing compound and a styryl group-containing compound.

In an embodiment, the fluorescent dopant may include a compound represented by Formula 501:

In Formula 501:

Ar₅₀₁, L₅₀₁ to L₅₀₃, R₅₀₁, and R₅₀₂ may each independently be a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a);

xd1 to xd3 may each independently be 0, 1, 2, or 3; and

xd4 may be 1, 2, 3, 4, 5, or 6.

In an embodiment, Ar₅₀₁ in Formula 501 may be a fused cyclic group (for example, an anthracene group, a chrysene group, or a pyrene group) in which three or more monocyclic groups are fused together.

In an embodiment, xd4 in Formula 501 may be 2.

In an embodiment, the fluorescent dopant may include at least one of Compounds FD1 to FD36, DPVBi, and DPAVBi.

Compounds FD1 to FD36 are as follows:

Delayed Fluorescence Material

In various embodiments, the emission layer may include a delayed fluorescence material.

The delayed fluorescence material used herein may be selected from compounds capable of emitting delayed fluorescence based on a delayed fluorescence emission mechanism.

The delayed fluorescence material included in the emission layer may act as a host or a dopant depending on the type of other materials included in the emission layer.

In an embodiment, the difference between the triplet energy level in electron volt (eV) of the delayed fluorescence material and the singlet energy level (eV) of the delayed fluorescence material may be greater than or equal to 0 eV and less than or equal to 0.5 eV. When the difference between the triplet energy level (eV) of the delayed fluorescence material and the singlet energy level (eV) of the delayed fluorescence material satisfies the above-described range, up-conversion from the triplet state to the singlet state of the delayed fluorescence materials may effectively occur, and thus, the emission efficiency of the light-emitting device 10 may be improved.

In an embodiment, the delayed fluorescence material may include i) a material including at least one electron donor (for example, a π electron-rich C₃-C₆₀ cyclic group, such as a carbazole group) and at least one electron acceptor (for example, a sulfoxide group, a cyano group, or a π electron-deficient nitrogen-containing C₁-C₆₀ cyclic group), and ii) a material including a C₈-C₆₀ polycyclic group in which two or more cyclic groups are fused while sharing boron (B).

In an embodiment, the delayed fluorescence material may include a fused cyclic compound represented by Formula 7:

In Formula 7:

X₇₁ may be C(R₇₄)(R₇₅), N(R₇₄), O, or S;

X₇₂ may be C(R₇₆)(R₇₇), N(R₇₆), O, or S;

CY₇₁ to CY₇₃ and L₇₁ to L₇₃ may each independently be a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a);

a71 to a73 may each independently be an integer from 0 to 5;

R₇₁ to R₇₇ may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group unsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkenyl group unsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkynyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ alkoxy group unsubstituted or substituted with at least one R_(10a), a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ aryloxy group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ arylthio group unsubstituted or substituted with at least one R_(10a), —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), or —P(═O)(Q₁)(Q₂);

b71 to b73 may each independently be an integer from 1 to 5;

n71 to n73 may each independently be an integer from 1 to 8; and

R_(10a) is the same as described herein.

In an embodiment, the delayed fluorescence material may include at least one of the compounds DF1 to DF10.

Compounds DF1 to DF10 are as follows:

Quantum Dot

The emission layer may include a quantum dot.

The quantum dot used herein refers to a crystal of a semiconductor compound, and may include any material capable of emitting light of various emission wavelengths according to the size of the crystal.

A diameter of the quantum dot may be, for example, in a range of about 1 nm to about 10 nm.

The quantum dot may be synthesized by a wet chemical process, a metal organic chemical vapor deposition process, a molecular beam epitaxy process, or any process similar thereto.

According to the wet chemical process, a precursor material is mixed with an organic solvent to grow a quantum dot particle crystal. When the crystal grows, the organic solvent naturally acts as a dispersant coordinated on the surface of the quantum dot crystal and controls the growth of the crystal so that the growth of quantum dot particles can be controlled through a process that is more easily performed than vapor deposition methods, such as metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE), and that has low cost.

The quantum dot may include at least one of a Group II-VI semiconductor compound, a Group III-V semiconductor compound, a Group III-VI semiconductor compound, a Group I-III-VI semiconductor compound, a Group IV-VI semiconductor compound, and a Group IV element or compound.

Examples of the Group II-VI semiconductor compound are at least one of a binary compound, such as CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, or MgS; a ternary compound, such as CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, or MgZnS; and a quaternary compound, such as CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, or HgZnSTe.

Examples of the Group III-V semiconductor compound are at least one of a binary compound, such as GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, or the like; a ternary compound, such as GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InNP, InAlP, InNAs, InNSb, InPAs, InPSb, or the like; and a quaternary compound, such as GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, or the like. Meanwhile, the Group III-V semiconductor compound may further include Group II elements. Examples of the Group III-V further including Group II elements are InZnP, InGaZnP, InAlZnP, etc.

Examples of the Group III-VI semiconductor compound are at least one of a binary compound, such as GaS, GaSe, Ga₂Se₃, GaTe, InS, InSe, In₂S₃, In₂Se₃, or InTe; and a ternary compound, such as InGaS₃, or InGaSe₃.

Examples of the Group I-III-VI semiconductor compound are at least one of a ternary compound, such as AgInS, AgInS₂, CuInS, CuInS₂, CuGaO₂, AgGaO₂, and/or AgAlO₂.

Examples of the Group IV-VI semiconductor compound are at least one of a binary compound, such as SnS, SnSe, SnTe, PbS, PbSe, PbTe, or the like; a ternary compound, such as SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, or the like; and a quaternary compound, such as SnPbSSe, SnPbSeTe, SnPbSTe, or the like.

The Group IV element or compound may include at least one of a single element compound, such as Si or Ge; and a binary compound, such as SiC or SiGe.

Each element included in a multi-element compound, such as the binary compound, ternary compound, and quaternary compound, may exist in a particle with a uniform concentration or a non-uniform concentration.

In some embodiments, the quantum dot may have a single structure or a dual core-shell structure. In the case of the quantum dot having a single structure, the concentration of each element included in the corresponding quantum dot may be uniform. In an embodiment, the material contained in the core and the material contained in the shell may be different from each other.

The shell of the quantum dot may act as a protective layer to prevent chemical degeneration of the core to maintain semiconductor characteristics and/or as a charging layer to impart electrophoretic characteristics to the quantum dot. The shell may be a single layer or a multi-layer. The interface between the core and the shell may have a concentration gradient that decreases toward the center of the element present in the shell.

Examples of the shell of the quantum dot are at least one of an oxide of metal, a metalloid, a non-metal, and a semiconductor compound. Examples of the oxide of metal, the metalloid, and the non-metal are at least one of a binary compound, such as SiO₂, Al₂O₃, TiO₂, ZnO, MnO, Mn₂O₃, Mn₃O₄, CuO, FeO, Fe₂O₃, Fe₃O₄, CoO, CO₃O₄, or NiO; and a ternary compound, such as MgAl₂O₄, CoFe₂O₄, NiFe₂O₄, or CoMn₂O₄. Examples of the semiconductor compound are, as described herein, at least one of a Group II-VI semiconductor compound; a Group III-V semiconductor compound; a Group III-VI semiconductor compound; a Group I-III-VI semiconductor compound; and a Group IV-VI semiconductor compound. In addition, the semiconductor compound may include at least one of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, and AlSb.

A full width at half maximum (FWHM) of an emission wavelength spectrum of the quantum dot may be about 45 nm or less, for example, about 40 nm or less, e.g., about 30 nm or less, and within these ranges, color purity and/or color gamut may be increased. In addition, since the light emitted through the quantum dot is emitted in all directions, a wide viewing angle can be improved.

In addition, the quantum dot may be a spherical particle, a pyramidal particle, a multi-arm particle, a cubic nanoparticle, a nanotube particle, a nanowire particle, a nanofiber particle, or a nanoplate particle.

Since the energy band gap can be adjusted by controlling the size of the quantum dot, light having various wavelength bands can be obtained from the quantum dot emission layer. Therefore, by using quantum dots of different sizes, a light-emitting display that emits light of various wavelengths may be implemented. In an embodiment, the size of the quantum dot may be selected from to emit red, green, and/or blue light. In addition, the size of the quantum dot may be configured to emit white light by combining light of various colors.

Electron Transport Region in Interlayer 130

The electron transport region may include the first electron transport layer as described above and the second electron transport layer as described above.

The electron transport region may include at least one of a buffer layer, a hole blocking layer, an electron control layer, and an electron injection layer.

For example, the electron transport region may have a structure of a first electron transport layer/a second electron transport layer/an electron injection layer, a hole blocking layer/a first electron transport layer/a second electron transport layer/an electron injection layer, an electron control layer/a first electron transport layer/a second electron transport layer/an electron injection layer, or a buffer layer/a first electron transport layer/a second electron transport layer/an electron injection layer sequentially stacked from the emission layer.

The electron transport region may include a metal-free compound including at least one π electron-deficient nitrogen-containing C₁-C₆₀ cyclic group in addition to the first compound and second compound as described above.

In an embodiment, the electron transport region may include a compound represented by Formula 601 below:

[Ar₆₀₁]_(xe11)-[(L₆₀₁)_(xe1)-R₆₀₁]_(xe21)  Formula 601

In Formula 601:

Ar₆₀₁ and L₆₀₁ may each independently be a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a);

xe11 may be 1, 2, or 3;

xe1 may be 0, 1, 2, 3, 4, or 5;

R₆₀₁ may be a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a), —Si(Q₆₀₁)(Q₆₀₂)(Q₆₀₃), —C(═O)(Q₆₀₁), —S(═O)₂(Q₆₀₁), or —P(═O)(Q₆₀₁)(Q₆₀₂);

Q₆₀₁ to Q₆₀₃ are the same as described in connection with Q₁;

xe21 may be 1, 2, 3, 4, or 5; and

at least one of Ar₆₀₁, L₆₀₁, and R₆₀₁ may each independently be a π electron-deficient nitrogen-containing C₁-C₆₀ cyclic group unsubstituted or substituted with at least one R_(10a).

For example, when xe11 in Formula 601 is 2 or more, two or more of Ar₆₀₁(s) may be linked via a single bond.

In an embodiment, Ar₆₀₁ in Formula 601 may be a substituted or unsubstituted anthracene group.

In an embodiment, the electron transport region may include a compound represented by Formula 601-1.

In Formula 601-1:

X₆₁₄ may be N or C(R₆₁₄), X₆₁₅ may be N or C(R₆₁₅), X₆₁₆ may be N or C(R₆₁₆), at least one of X₆₁₄ to X₆₁₆ may be N;

L₆₁₁ to L₆₁₃ are the same as described in connection with L₆₀₁;

xe611 to xe613 are the same as described in connection with xe1;

R₆₁₁ to R₆₁₃ are the same as described in connection with R₆₀₁; and

R₆₁₄ to R₆₁₆ may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a), or a C₁-C₆₀ heterocyclic group substituted or unsubstituted at least one R_(10a).

For example, xe1 and xe611 to xe613 in Formulae 601 and 601-1 may each independently be 0, 1, or 2.

The electron transport region may include at least one of Compounds ET1 to ET45, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), Alq₃, BAlq, TAZ, and NTAZ.

Compounds ET1 to ET45 are as follows:

The thickness of the electron transport region may be from about 50 Å to about 5,000 Å, for example, from about 100 Å to about 4,000 Å. When the electron transport region includes a buffer layer, a hole blocking layer, an electron control layer, or any combination thereof, the thicknesses of the buffer layer, the hole blocking layer, or the electron control layer may each independently be from about 20 Å to about 1000 Å, for example, from about 30 Å to about 300 Å. When the thicknesses of the buffer layer, the hole blocking layer, and/or the electron control layer are within these ranges, satisfactory electron transporting characteristics may be obtained without a substantial increase in driving voltage.

The electron transport region (for example, the second electron transport layer in the electron transport region) may further include, in addition to the materials as described above, a metal-containing material.

The electron transport region may include an electron injection layer that facilitates the injection of electrons from the second electrode 150. The electron injection layer may directly contact the second electrode 150.

The electron injection layer may have: i) a single-layered structure consisting of a single layer consisting of a single material, ii) a single-layered structure consisting of a single layer consisting of a plurality of different materials, or iii) a multi-layered structure including a plurality of layers including different materials.

The electron injection layer may include at least one of an alkali metal, alkaline earth metal, a rare earth metal, an alkali metal-containing compound, alkaline earth metal-containing compound, a rare earth metal-containing compound, an alkali metal complex, alkaline earth metal complex, and a rare earth metal complex.

The alkali metal may include at least one of Li, Na, K, Rb, and Cs. The alkaline earth metal may include at least one of Mg, Ca, Sr, and Ba. The rare earth metal may include at least one of Sc, Y, Ce, Tb, Yb, and Gd.

The alkali metal-containing compound, the alkaline earth metal-containing compound, and the rare earth metal-containing compound may be oxides, halides (for example, fluorides, chlorides, bromides, or iodides), or tellurides of at least one of the alkali metal, the alkaline earth metal, and the rare earth metal.

The alkali metal-containing compound may include at least one of alkali metal oxides, such as Li₂O, Cs₂O, or K₂O, and alkali metal halides, such as LiF, NaF, CsF, KF, LiI, NaI, CsI, or KI. The alkaline earth metal-containing compound may include alkaline earth metal oxides, such as BaO, SrO, CaO, Ba_(x)Sr_(1-x)O (x is a real number satisfying the condition of 0<x<1), Ba_(x)Ca_(1-x)O (x is a real number satisfying the condition of 0<x<1), or the like. The rare earth metal-containing compound may include at least one of YbF₃, ScF₃, Sc₂O₃, Y₂O₃, Ce₂O₃, GdF₃, TbF₃, YbI₃, ScI₃, and TbI₃. In an embodiment, the rare earth metal-containing compound may include lanthanide metal telluride. Examples of the lanthanide metal telluride are LaTe, CeTe, PrTe, NdTe, PmTe, SmTe, EuTe, GdTe, TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, LuTe, La₂Te₃, Ce₂Te₃, Pr₂Te₃, Nd₂Te₃, Pm₂Te₃, Sm₂Te₃, Eu₂Te₃, Gd₂Te₃, Tb₂Te₃, Dy₂Te₃, Ho₂Te₃, Er₂Te₃, Tm₂Te₃, Yb₂Te₃, and Lu₂Te₃.

The alkali metal complex, the alkaline earth-metal complex, and the rare earth metal complex may include i) one of ions of the alkali metal, the alkaline earth metal, and the rare earth metal and ii), as a ligand bonded to the metal ion, for example, at least one of a hydroxyquinoline, a hydroxyisoquinoline, a hydroxybenzoquinoline, a hydroxyacridine, a hydroxyphenanthridine, a hydroxyphenyloxazole, a hydroxyphenylthiazole, a hydroxyphenyloxadiazole, a hydroxyphenylthiadiazole, a hydroxyphenylpyridine, a hydroxyphenylbenzimidazole, a hydroxyphenylbenzothiazole, a bipyridine, a phenanthroline, and a cyclopentadiene.

The electron injection layer may consist of at least one of an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal-containing compound, an alkaline earth metal-containing compound, a rare earth metal-containing compound, an alkali metal complex, an alkaline earth metal complex, and a rare earth metal complex, as described above. In an embodiment, the electron injection layer may further include an organic material (for example, a compound represented by Formula 601).

In an embodiment, the electron injection layer may consist of i) an alkali metal-containing compound (for example, an alkali metal halide), ii) a) an alkali metal-containing compound (for example, an alkali metal halide); and b) at least one of an alkali metal, an alkaline earth metal, and a rare earth metal. In an embodiment, the electron injection layer may be a KI:Yb co-deposited layer, an RbI:Yb co-deposited layer, or the like.

When the electron injection layer further includes at least one of an organic material, alkali metal, alkaline earth metal, rare earth metal, an alkali metal-containing compound, an alkaline earth metal-containing compound, a rare earth metal-containing compound, an alkali metal complex, an alkaline earth metal complex, and a rare earth metal complex, these elements may be homogeneously or non-homogeneously dispersed in a matrix including the organic material.

A thickness of the electron injection layer may be in a range of about 1 Å to about 100 Å, and, for example, about 3 Å to about 90 Å. When the thickness of the electron injection layer is within the range described above, the electron injection layer may have satisfactory electron injection characteristics without a substantial increase in driving voltage.

Second Electrode 150

The second electrode 150 may be located on the interlayer 130. The second electrode 150 may be a cathode, which is an electron injection electrode. As the material for the second electrode 150, at least one of a metal, an alloy, and an electrically conductive compound, each having a low work function, may be used.

In an embodiment, the second electrode 150 may include at least one of lithium (Li), silver (Ag), magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), ytterbium (Yb), silver-ytterbium (Ag—Yb), ITO, and IZO. The second electrode 150 may be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode.

The second electrode 150 may have a single-layered structure or a multi-layered structure including two or more layers.

Capping Layer

A first capping layer may be located outside the first electrode 110, and/or a second capping layer may be located outside the second electrode 150. For instance, the light-emitting device 10 may have a structure in which the first capping layer, the first electrode 110, the interlayer 130, and the second electrode 150 are sequentially stacked in this stated order; a structure in which the first electrode 110, the interlayer 130, the second electrode 150, and the second capping layer are sequentially stacked in this stated order; or a structure in which the first capping layer, the first electrode 110, the interlayer 130, the second electrode 150, and the second capping layer are sequentially stacked in this stated order.

Light generated in an emission layer of the interlayer 130 of the light-emitting device 10 may be extracted toward the outside through the first electrode 110, which may be a semi-transmissive electrode or a transmissive electrode, and the first capping layer or light generated in an emission layer of the interlayer 130 of the light-emitting device 10 may be extracted toward the outside through the second electrode 150, which may be a semi-transmissive electrode or a transmissive electrode, and the second capping layer.

The first capping layer and the second capping layer may increase external emission efficiency according to the principle of constructive interference. Accordingly, the light extraction efficiency of the light-emitting device 10 can be increased such that the emission efficiency of the light-emitting device 10 may be improved.

Each of the first capping layer and second capping layer may include a material having a refractive index (at 589 nm) of 1.6 or more.

The first capping layer and the second capping layer may each independently be an organic capping layer including an organic material, an inorganic capping layer including an inorganic material, or an organic-inorganic composite capping layer including an organic material and an inorganic material.

At least one of the first capping layer and the second capping layer may each independently include at least one of carbocyclic compounds, heterocyclic compounds, amine group-containing compounds, porphyrine derivatives, phthalocyanine derivatives, a naphthalocyanine derivatives, alkali metal complexes, and alkaline earth metal complexes. The carbocyclic compound, the heterocyclic compound, and the amine group-containing compound may be optionally substituted with a substituent containing at least one of O, N, S, Se, Si, F, Cl, Br, and I. In an embodiment, at least one of the first capping layer and the second capping layer may each independently include an amine group-containing compound.

In an embodiment, at least one of the first capping layer and the second capping layer may each independently include at least one of a compound represented by Formula 201 and a compound represented by Formula 202.

In an embodiment, at least one of the first capping layer and the second capping layer may each independently include at least one of a compound selected from Compounds HT28 to HT33, Compounds CP1 to CP6, and β-NPB, but embodiments are not limited thereto.

Compounds CP1 to CP6 are as follows:

Electronic Apparatus

The light-emitting device may be included in various electronic apparatuses. In an embodiment, the electronic apparatus including the light-emitting device may be a light-emitting apparatus, an authentication apparatus, or the like.

The electronic apparatus (for example, light-emitting apparatus) may further include, in addition to the light-emitting device, i) a color filter, ii) a color conversion layer, or iii) a color filter and a color conversion layer. The color filter and/or the color conversion layer may be located in at least one traveling direction of light emitted from the light-emitting device. In an embodiment, the light emitted from the light-emitting device may be blue light or white light. The light-emitting device may be the same as described above. In an embodiment, the color conversion layer may include quantum dots. The quantum dot may be, for example, a quantum dot as described herein.

The electronic apparatus may include a first substrate. The first substrate may include a plurality of subpixel areas, the color filter may include a plurality of color filter areas respectively corresponding to the subpixel areas, and the color conversion layer may include a plurality of color conversion areas respectively corresponding to the subpixel areas.

A pixel-defining film may be located among the subpixel areas to define each of the subpixel areas.

The color filter may further include a plurality of color filter areas and light-blocking patterns located among the color filter areas. The color conversion layer may include a plurality of color conversion areas and light-blocking patterns located among the color conversion areas.

The color filter areas (or the color conversion areas) may include a first area emitting first color light, a second area emitting second color light, and/or a third area emitting third color light. The first color light, the second color light, and/or the third color light may have different maximum emission wavelengths from one another. In an embodiment, the first color light may be red light, the second color light may be green light, and the third color light may be blue light. In an embodiment, the color filter areas (or the color conversion areas) may include quantum dots. For instance, the first area may include a red quantum dot, the second area may include a green quantum dot, and the third area may not include a quantum dot. The quantum dot is the same as described herein. The first area, the second area, and/or the third area may each include a scatterer.

In an embodiment, the light-emitting device may emit first light, the first area may absorb the first light to emit first first-color light, the second area may absorb the first light to emit second first-color light, and the third area may absorb the first light to emit third first-color light. In this regard, the first first-color light, the second first-color light, and the third-first light may have different maximum emission wavelengths from one another. For example, the first light may be blue light, the first first-color light may be red light, the second first-color light may be green light, and the third first-color light may be blue light.

The electronic apparatus may further include a thin-film transistor in addition to the light-emitting device as described above. The thin-film transistor may include a source electrode, a drain electrode, and an active layer. Any one of the source electrode and the drain electrode may be electrically connected to any one of the first electrode and the second electrode of the light-emitting device.

The thin-film transistor may include a gate electrode, a gate insulating film, etc.

The active layer may include crystalline silicon, amorphous silicon, organic semiconductor, oxide semiconductor, or the like.

The electronic apparatus may further include a sealing portion for sealing the light-emitting device. The sealing portion and/or the color conversion layer may be placed between the color filter and the light-emitting device. The sealing portion allows light from the light-emitting device to be extracted to the outside, while simultaneously preventing ambient air and moisture from penetrating into the light-emitting device. The sealing portion may be a sealing substrate including a transparent glass or a plastic substrate. The sealing portion may be a thin-film encapsulation layer including at least one layer of an organic layer and/or an inorganic layer. When the sealing portion is a thin film encapsulation layer, the electronic apparatus may be flexible.

Various functional layers may be additionally located on the sealing portion, in addition to the color filter and/or the color conversion layer, according to the use of the electronic apparatus. The functional layers may include a touch screen layer, a polarizing layer, and/or the like. The touch screen layer may be a pressure-sensitive touch screen layer, a capacitive touch screen layer, and/or an infrared touch screen layer. The authentication apparatus may be, for example, a biometric authentication apparatus that authenticates an individual using biometric information of a living body (for example, fingertips, pupils, etc.).

The authentication apparatus may further include, in addition to the light-emitting device, a biometric information collector.

The electronic apparatus may be applied to various displays, light sources, lighting, personal computers (for example, a mobile personal computer), mobile phones, digital cameras, electronic organizers, electronic dictionaries, electronic game machines, medical instruments (for example, electronic thermometers, sphygmomanometers, blood glucose meters, pulse measurement devices, pulse wave measurement devices, electrocardiogram displays, ultrasonic diagnostic devices, or endoscope displays), fish finders, various measuring instruments, meters (for example, meters for a vehicle, an aircraft, and a vessel), projectors, and the like.

FIG. 2 is a cross-sectional view showing a light-emitting apparatus according to an embodiment.

The light-emitting apparatus 180 of FIG. 2 includes a substrate 100, a thin-film transistor (TFT) 200, a light-emitting device 10, and an encapsulation portion 300 that seals the light-emitting device 10.

The substrate 100 may be a plastic substrate, a glass substrate, or a metal substrate. The substrate 100 may be flexible, rigid, or include at least one flexible area and at least one rigid area. A buffer layer 210 may be formed on the substrate 100. The buffer layer 210 may prevent penetration of impurities through the substrate 100 and may provide a flat surface on the substrate 100.

The TFT 200 may be located on the buffer layer 210. The TFT 200 may include an active layer 220, a gate electrode 240, a source electrode 260, and a drain electrode 270.

The active layer 220 may include an inorganic semiconductor, such as silicon or polysilicon, an organic semiconductor, or an oxide semiconductor, and may include a source region, a drain region and a channel region.

A gate insulating film 230 for insulating the active layer 220 from the gate electrode 240 may be located on the active layer 220, and the gate electrode 240 may be located on the gate insulating film 230.

An interlayer insulating film 250 is located on the gate electrode 240. The interlayer insulating film 250 may be placed between the gate electrode 240 and the source electrode 260 to insulate the gate electrode 240 from the source electrode 260 and between the gate electrode 240 and the drain electrode 270 to insulate the gate electrode 240 from the drain electrode 270.

The source electrode 260 and the drain electrode 270 may be located on the interlayer insulating film 250. The interlayer insulating film 250 and the gate insulating film 230 may be formed to expose the source region and the drain region of the active layer 220, and the source electrode 260 and the drain electrode 270 may be in contact with the exposed portions of the source region and the drain region of the active layer 220.

The TFT 200 is electrically connected to a light-emitting device 10 to drive the light-emitting device 10, and is covered by a passivation layer 280. The passivation layer 280 may include at least one of an inorganic insulating film and an organic insulating film. A light-emitting device 10 is provided on the passivation layer 280. The light-emitting device 10 may include a first electrode 110, an interlayer 130, and a second electrode 150.

The first electrode 110 may be formed on the passivation layer 280. The passivation layer 280 does not completely cover the drain electrode 270 and exposes a portion of the drain electrode 270. The first electrode 110 is connected to the exposed portion of the drain electrode 270.

A pixel defining layer 290 containing an insulating material may be located on the first electrode 110. The pixel defining layer 290 exposes a region of the first electrode 110, and an interlayer 130 may be formed on the exposed region of the first electrode 110. The pixel defining layer 290 may be a polyimide or polyacrylic organic film. At least some layers of the interlayer 130 may extend beyond the upper portion of the pixel defining layer 290 to be located in the form of a common layer with respect to a plurality of pixels/sub-pixels.

The second electrode 150 may be located on the interlayer 130, and a capping layer 170 may be additionally formed on the second electrode 150. The capping layer 170 may be formed to cover the second electrode 150.

The encapsulation portion 300 may be located on the capping layer 170. The encapsulation portion 300 may be located on a light-emitting device 10 to protect the light-emitting device 10 from moisture and/or oxygen. The encapsulation portion 300 may include: an inorganic film including at least one of silicon nitride (SiN_(x)), silicon oxide (SiO_(x)), indium tin oxide, and indium zinc oxide; an organic film including at least one of polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene, polyarylate, hexamethyldisiloxane, an acrylic resin (for example, polymethyl methacrylate, polyacrylic acid, or the like), and an epoxy-based resin (for example, aliphatic glycidyl ether (AGE), or the like); and/or a combination of the inorganic film and the organic film.

FIG. 3 shows a cross-sectional view showing a light-emitting apparatus according to an embodiment.

The light-emitting apparatus 190 of FIG. 3 is the same as the light-emitting apparatus 180 of FIG. 2, except that a light-blocking pattern 500 and a functional region 400 are additionally located on the encapsulation portion 300. The functional region 400 may be a combination of i) a color filter area, ii) a color conversion area, or iii) a combination of the color filter area and the color conversion area. In an embodiment, the light-emitting device 10 included in the light-emitting apparatus 190 of FIG. 3 may be a tandem light-emitting device.

Manufacture Method

Respective layers included in the hole transport region, the emission layer, and respective layers included in the electron transport region may be formed in a certain region by using one or more suitable methods selected from vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) deposition, ink-jet printing, laser-printing, and laser-induced thermal imaging.

When layers constituting the hole transport region, an emission layer, and layers constituting the electron transport region are formed by vacuum deposition, the deposition may be performed at a deposition temperature of about 100° C. to about 500° C., a vacuum degree of about 10⁻⁸ torr to about 10⁻³ torr, and a deposition speed of about 0.01 Å/sec to about 100 Å/sec, depending on a material to be included in a layer to be formed and the structure of a layer to be formed.

Definition of Terms

As used herein, the term “atom” may mean an element or its corresponding radical bonded to one or more other atoms.

The terms “hydrogen” and “deuterium” refer to their respective atoms and corresponding radicals with the deuterium radical abbreviated “—D”, and the terms “—F, —Cl, —Br, and —I” are radicals of, respectively, fluorine, chlorine, bromine, and iodine.

As used herein, a substituent for a monovalent group, e.g., alkyl, may also be, independently, a substituent for a corresponding divalent group, e.g., alkylene.

The term “C₃-C₆₀ carbocyclic group” as used herein refers to a cyclic group consisting of carbon only and having three to sixty carbon atoms as ring-forming atoms, and the term “C₁-C₆₀ heterocyclic group” as used herein refers to a cyclic group that has one to sixty carbon atoms as ring-forming atoms and further has, in addition to carbon, a heteroatom. The C₃-C₆₀ carbocyclic group and the C₁-C₆₀ heterocyclic group may each be a monocyclic group consisting of one ring or a polycyclic group in which two or more rings are fused with each other. In an embodiment, the number of ring-forming atoms of the C₁-C₆₀ heterocyclic group may be from 3 to 61.

The term “cyclic group” as used herein may include the C₃-C₆₀ carbocyclic group, and the C₁-C₆₀ heterocyclic group.

The term “n electron-rich C₃-C₆₀ cyclic group” as used herein refers to a cyclic group that has three to sixty carbon atoms and does not include *—N═*′ as a ring-forming moiety, and the term “n electron-deficient nitrogen-containing C₁-C₆₀ cyclic group” as used herein refers to a heterocyclic group that has one to sixty carbon atoms and includes *—N═*′ as a ring-forming moiety.

For example:

the C₃-C₆₀ carbocyclic group may be i) group T1 or ii) a fused cyclic group in which two or more groups T1 are fused with each other (for example, a cyclopentadiene group, an adamantane group, a norbornane group, a benzene group, a pentalene group, a naphthalene group, an azulene group, an indacene group, acenaphthylene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a perylene group, a pentaphene group, a heptalene group, a naphthacene group, a picene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, an indene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, an indenophenanthrene group, or an indenoanthracene group);

the C₁-C₆₀ heterocyclic group may be i) group T2, ii) a fused cyclic group in which two or more groups T2 are fused with each other, or iii) a fused cyclic group in which at least one group T2 and at least one group T1 are fused with each other (for example, a pyrrole group, a thiophene group, a furan group, an indole group, a benzoindole group, a naphthoindole group, an isoindole group, a benzoisoindole group, a naphthoisoindole group, a benzosilole group, a benzothiophene group, a benzofuran group, a carbazole group, a dibenzosilole group, a dibenzothiophene group, a dibenzofuran group, an indenocarbazole group, an indolocarbazole group, a benzofurocarbazole group, a benzothienocarbazole group, a benzosilolocarbazole group, a benzoindolocarbazole group, a benzocarbazole group, a benzonaphthofuran group, a benzonaphthothiophene group, a benzonaphthosilole group, a benzofurodibenzofuran group, a benzofurodibenzothiophene group, a benzothienodibenzothiophene group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzoisoxazole group, a benzothiazole group, a benzoisothiazole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a quinoxaline group, a benzoquinoxaline group, a quinazoline group, a benzoquinazoline group, a phenanthroline group, a cinnoline group, a phthalazine group, a naphthyridine group, an imidazopyridine group, an imidazopyrimidine group, an imidazotriazine group, an imidazopyrazine group, an imidazopyridazine group, an azacarbazole group, an azafluorene group, an azadibenzosilole group, an azadibenzothiophene group, an azadibenzofuran group, etc.);

the π electron-rich C₃-C₆₀ cyclic group may be i) group T1, ii) a fused cyclic group in which two or more groups T1 are fused with each other, iii) group T3, iv) a fused cyclic group in which two or more groups T3 are fused with each other, or v) a fused cyclic group in which at least one group T3 and at least one group T1 are fused with each other (for example, the C₃-C₆₀ carbocyclic group, a 1h-pyrrol group, a silole group, a borole group, a 2H-pyrrole group, a 3H-pyrrole group, a thiophene group, a furan group, an indole group, a benzoindole group, a naphthoindole group, an isoindole group, a benzoisoindole group, a naphthoisoindole group, a benzosilole group, a benzothiophene group, a benzofuran group, a carbazole group, a dibenzosilole group, a dibenzothiophene group, a dibenzofuran group, an indenocarbazole group, an indolocarbazole group, a benzofurocarbazole group, a benzothienocarbazole group, a benzosilolocarbazole group, a benzoindolocarbazole group, a benzocarbazole group, a benzonaphthofuran group, a benzonaphthothiophene group, a benzonaphthosilole group, a benzofurodibenzofuran group, a benzofurodibenzothiophene group, a benzothienodibenzothiophene group, etc.);

the π electron-deficient nitrogen-containing C₁-C₆₀ cyclic group may be i) group T4, ii) a fused cyclic group in which two or more group T4 are fused with each other, iii) a fused cyclic group in which at least one group T4 and at least one group T1 are fused with each other, iv) a fused cyclic group in which at least one group T4 and at least one group T3 are fused with each other, or v) a fused cyclic group in which at least one group T4, at least one group T1, and at least one group T3 are fused with one another (for example, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzoisoxazole group, a benzothiazole group, a benzoisothiazole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a quinoxaline group, a benzoquinoxaline group, a quinazoline group, a benzoquinazoline group, a phenanthroline group, a cinnoline group, a phthalazine group, a naphthyridine group, an imidazopyridine group, an imidazopyrimidine group, an imidazotriazine group, an imidazopyrazine group, an imidazopyridazine group, an azacarbazole group, an azafluorene group, an azadibenzosilole group, an azadibenzothiophene group, an azadibenzofuran group, etc.);

group T1 may be a cyclopropane group, a cyclobutane group, a cyclopentane group, a cyclohexane group, a cycloheptane group, a cyclooctane group, a cyclobutene group, a cyclopentene group, a cyclopentadiene group, a cyclohexene group, a cyclohexadiene group, a cycloheptene group, an adamantane group, a norbornane (or a bicyclo[2.2.1]heptane) group, a norbornene group, a bicyclo[1.1.1]pentane group, a bicyclo[2.1.1]hexane group, a bicyclo[2.2.2]octane group, or a benzene group;

group T2 is a furan group, a thiophene group, a 1H-pyrrole group, a silole group, a borole group, a 2H-pyrrole group, a 3H-pyrrole group, an imidazole group, a pyrazole group, a triazole group, a tetrazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, an azasilole group, an azaborole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, tetrazine group, a pyrrolidine group, an imidazolidine group, a dihydropyrrole group, a piperidine group, a tetrahydro pyridine group, a dihydropyridine group, a hexahydropyrimidine group, a tetrahydropyrimidine group, a dihydropyrimidine group, a piperazine group, a tetrahydro pyrazine group, a dihydropyrazine group, a tetrahydro pyridazine group, or a dihydropyridazine group;

group T3 may be a furan group, a thiophene group, a 1H-pyrrole group, a silole group, or a borole group; and

group T4 may be a 2H-pyrrole group, a 3H-pyrrole group, an imidazole group, a pyrazole group, a triazole group, a tetrazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, an azasilole group, an azaborole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, or a tetrazine group.

The terms “the cyclic group, the C₃-C₆₀ carbocyclic group, the C₁-C₆₀ heterocyclic group, the π electron-rich C₃-C₆₀ cyclic group, or the π electron-deficient nitrogen-containing C₁-C₆₀ cyclic group” as used herein refer to a group fused to any cyclic group or a polyvalent group (for example, a divalent group, a trivalent group, a tetravalent group, etc.), depending on the structure of a formula in connection with which the terms are used. In an embodiment, “a benzene group” may be a benzo group, a phenyl group, a phenylene group, or the like, which may be easily understood by one of ordinary skill in the art according to the structure of a formula including the “benzene group.”

Examples of the monovalent C₃-C₆₀ carbocyclic group and the monovalent C₁-C₆₀ heterocyclic group are a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic fused polycyclic group, and a monovalent non-aromatic fused heteropolycyclic group, and examples of the divalent C₃-C₆₀ carbocyclic group and the monovalent C₁-C₆₀ heterocyclic group are Examples of the, C₃-C₁₀ cycloalkylene group, a C₁-C₁₀heterocycloalkylene group, a C₃-C₁₀ cycloalkenylene group, a C₁-C₁₀heterocycloalkenylene group, a C₆-C₆₀ arylene group, a C₁-C₆₀ heteroarylene group, a divalent non-aromatic fused polycyclic group, and a substituted or unsubstituted divalent non-aromatic fused heteropolycyclic group.

The term “C₁-C₆₀ alkyl group” as used herein refers to a linear or branched aliphatic hydrocarbon monovalent group that has one to sixty carbon atoms, and examples thereof are a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, neopentyl group, an isopentyl group, a sec-pentyl group, 3-pentyl group, a sec-isopentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isooctyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an isononyl group, a sec-nonyl group, a tert-nonyl group, an n-decyl group, an isodecyl group, a sec-decyl group, and a tert-decyl group. The term “C₁-C₆₀ alkylene group” as used herein refers to a divalent group having a structure corresponding to the C₁-C₆₀ alkyl group.

The term “C₂-C₆₀ alkenyl group” as used herein refers to a monovalent hydrocarbon group having at least one carbon-carbon double bond in the middle or at the terminus of the C₂-C₆₀ alkyl group, and examples thereof are an ethenyl group, a propenyl group, and a butenyl group. The term “C₂-C₆₀ alkenylene group” as used herein refers to a divalent group having a structure corresponding to the C₂-C₆₀ alkenyl group.

The term “C₂-C₆₀ alkynyl group” as used herein refers to a monovalent hydrocarbon group having at least one carbon-carbon triple bond in the middle or at the terminus of the C₂-C₆₀ alkyl group, and examples thereof include an ethynyl group, and a propynyl group. The term “C₁-C₆₀ alkynylene group” as used herein refers to a divalent group having a structure corresponding to the C₁-C₆₀ alkynyl group.

The term “C₁-C₆₀ alkoxy group” as used herein refers to a monovalent group represented by -OA₁₀₁ (wherein A₁₀₁ is the C₁-C₆₀ alkyl group), and examples thereof include a methoxy group, an ethoxy group, and an isopropyloxy group.

The term “C₃-C₁₀ cycloalkyl group” as used herein refers to a monovalent saturated hydrocarbon cyclic group having 3 to 10 carbon atoms, and examples thereof are a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group (or bicyclo[2.2.1]heptyl group), a bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, and a bicyclo[2.2.2]octyl group. The term “C₃-C₁₀ cycloalkylene group” as used herein refers to a divalent group having a structure corresponding to the C₃-C₁₀ cycloalkyl group.

The term “C₁-C₁₀ heterocycloalkyl group” as used herein refers to a monovalent cyclic group that further includes, in addition to a carbon atom, at least one heteroatom as a ring-forming atom and has 1 to 10 carbon atoms, and examples thereof are a 1,2,3,4-oxatriazolidinyl group, a tetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkylene group” as used herein refers to a divalent group having a structure corresponding to the C₁-C₁₀ heterocycloalkyl group.

The term “C₃-C₁₀ cycloalkenyl group” used herein refers to a monovalent cyclic group that has three to ten carbon atoms and at least one carbon-carbon double bond in the ring thereof and no aromaticity, and examples thereof are a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenyl group. The term “C₃-C₁₀ cycloalkenylene group” as used herein refers to a divalent group having a structure corresponding to the C₃-C₁₀ cycloalkenyl group.

The term “C₁-C₁₀ heterocycloalkenyl group” as used herein refers to a monovalent cyclic group that has, in addition to a carbon atom, at least one heteroatom as a ring-forming atom, 1 to 10 carbon atoms, and at least one carbon-carbon double bond in the cyclic structure thereof. Examples of the C₁-C₁₀ heterocycloalkenyl group include a 4,5-dihydro-1,2,3,4-oxatriazolyl group, a 2,3-dihydrofuranyl group, and a 2,3-dihydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkenylene group” as used herein refers to a divalent group having a structure corresponding to the C₁-C₁₀ heterocycloalkenyl group.

The term “C₆-C₆₀ aryl group” as used herein refers to a monovalent group having a carbocyclic aromatic system having six to sixty carbon atoms, and the term “C₆-C₆₀ arylene group” as used herein refers to a divalent group having a carbocyclic aromatic system having six to sixty carbon atoms. Examples of the C₆-C₆₀ aryl group are a phenyl group, a pentalenyl group, a naphthyl group, an azulenyl group, an indacenyl group, an acenaphthyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a heptalenyl group, a naphthacenyl group, a picenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, and an ovalenyl group. When the C₆-C₀ aryl group and the C₆-C₆₀ arylene group each include two or more rings, the rings may be fused with each other.

The term “C₁-C₆₀ heteroaryl group” as used herein refers to a monovalent group having a heterocyclic aromatic system that has, in addition to a carbon atom, at least one heteroatom as a ring-forming atom, and 1 to 60 carbon atoms. The term “C₁-C₆₀ heteroarylene group” as used herein refers to a divalent group having a heterocyclic aromatic system that has, in addition to a carbon atom, at least one heteroatom as a ring-forming atom, and 1 to 60 carbon atoms. Examples of the C₁-C₆₀ heteroaryl group are a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, a benzoquinolinyl group, an isoquinolinyl group, a benzoisoquinolinyl group, a quinoxalinyl group, a benzoquinoxalinyl group, a quinazolinyl group, a benzoquinazolinyl group, a cinnolinyl group, a phenanthrolinyl group, a phthalazinyl group, and a naphthyridinyl group. When the C₁-C₆₀ heteroaryl group and the C₁-C₆₀ heteroarylene group each include two or more rings, the rings may be fused with each other.

The term “monovalent non-aromatic fused polycyclic group” as used herein refers to a monovalent group having two or more rings fused to each other, only carbon atoms (for example, having 8 to 60 carbon atoms) as ring-forming atoms, and no aromaticity in its molecular structure when considered as a whole. Examples of the monovalent non-aromatic fused polycyclic group are an indenyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, an indenophenanthrenyl group, and an indenon anthracenyl group. The term “divalent non-aromatic fused polycyclic group” as used herein refers to a divalent group having a structure corresponding to a monovalent non-aromatic fused polycyclic group.

The term “monovalent non-aromatic fused heteropolycyclic group” as used herein refers to a monovalent group having two or more rings fused to each other, at least one heteroatom other than carbon atoms (for example, having 1 to 60 carbon atoms), as a ring-forming atom, and no aromaticity in its molecular structure when considered as a whole. Examples of the monovalent non-aromatic fused heteropolycyclic group are a 9,10-dihydroacridinyl group and a 9H-xanthenyl group. The term “divalent non-aromatic fused heteropolycyclic group” as used herein refers to a divalent group having a structure corresponding to a monovalent non-aromatic fused heteropolycyclic group.

The term “C₆-C₆₀ aryloxy group” as used herein indicates -OA₁₀₂ (wherein A₁₀₂ is the C₆-C₆₀ aryl group), and the term “C₆-C₆₀ arylthio group” as used herein refers to -SA₁₀₃ (wherein A₁₀₃ is the C₆-C₆₀ aryl group).

The term “C₇-C₆₀ arylalkyl group” as used herein refers to -A₁₀₄A₁₀₅ (here, A₁₀₄ is a C₁-C₅₄ alkylene group, and A₁₀₅ is a C₆-C₅₉ aryl group), and the term “C₂-C₆₀ heteroarylalkyl group” as used herein refers to -A₁₀₆A₁₀₇ (here, A₁₀₆ is a C₁-C₅₉ alkylene group, and A₁₀₇ is a C₁-C₅₉ heteroaryl group).

The term “R_(10a)” as used herein refers to:

deuterium (—D), —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or a nitro group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, or C₁-C₆₀ alkoxy group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀ arylalkyl group, a C₂-C₆₀ heteroarylalkyl group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), —P(═O)(Q₁₁)(Q₁₂), or any combination thereof;

a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, or a C₆-C₆₀ arylthio group, a C₇-C₆₀ arylalkyl group, or a C₂-C₆₀ heteroarylalkyl group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀ arylalkyl group, a C₂-C₆₀ heteroarylalkyl group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), —P(═O)(Q₂₁)(Q₂₂), or any combination thereof, or

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), or —P(═O)(Q₃₁)(Q₃₂).

Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ used herein may each independently be: hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; a C₁-C₆₀ alkyl group; a C₂-C₆₀ alkenyl group; a C₂-C₆₀ alkynyl group; a C₁-C₆₀ alkoxy group; or a C₃-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group, each unsubstituted or substituted with deuterium, —F, a cyano group, a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkoxy group, a phenyl group, a biphenyl group, or any combination thereof, a C₇-C₆₀ arylalkyl group; or a C₂-C₆₀ heteroarylalkyl group.

The term “hetero atom” as used herein refers to any atom other than a carbon atom. Examples of the heteroatom are at least one of O, S, N, P, Si, B, Ge, and Se.

The third-row transition metal used herein includes hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), and the like.

The term “Ph” as used herein refers to a phenyl group, the term “Me” as used herein refers to a methyl group, the term “Et” as used herein refers to an ethyl group, the term “ter-Bu” or “But” as used herein refers to a tert-butyl group, and the term “OMe” as used herein refers to a methoxy group.

The term “biphenyl group” as used herein refers to “a phenyl group substituted with a phenyl group.” For example, the “biphenyl group” is a substituted phenyl group having a C₆-C₆₀ aryl group as a substituent.

The term “terphenyl group” as used herein refers to “a phenyl group substituted with a biphenyl group.” For instance, the “terphenyl group” is a substituted phenyl group having, as a substituent, a C₆-C₆₀ aryl group substituted with a C₆-C₆₀ aryl group.

The symbols “*” and “*′” as used herein, unless defined otherwise, each refer to a binding site to a neighboring atom in a corresponding formula or moiety.

Hereinafter, a light-emitting device according to some embodiments will be described in detail with reference to Comparative Examples.

Comparative Example 1

An ITO glass substrate was cut to a size of 50 mm×50 mm×0.7 mm, sonicated with acetone, isopropyl alcohol, and pure water each for 10 minutes, and then cleaned by exposure to ultraviolet rays and ozone for 10 minutes. The ITO substrate was then provided to a vacuum deposition apparatus.

1 weight % of NDP-9 was used to be co-deposited on Compound HTL-1 to form a hole injection layer having a thickness of 100 Å, and HTL-1 was deposited thereon to form a first hole transport layer having a thickness of 600 Å. HTL-2 was vacuum-deposited on the first hole transport layer to form a second hole transport layer having a thickness of 50 Å.

H-1 as a host and DF10 as a dopant were co-deposited on the second hole transport layer to a weight ratio of 97:3 to form an emission layer having a thickness of 300 Å. ETL-1 was then vacuum-deposited on the emission layer to form a first electron transport layer having a thickness of 50 Å. ETL-2 and lithium quinolate (LiQ) were co-deposited on the first electron transport layer to a weight ratio of 1:1 to form a second electron transport layer having a thickness of 310 Å. LiF was deposited on the second electron transport layer to form an electron injection layer having a thickness of 8 Å, and Al was deposited thereon to form a cathode having a thickness of 1,000 Å, thereby completing the manufacture of a light-emitting device.

Comparative Examples 2 to 5 and Examples 1 to 12

Light-emitting devices of Comparative Examples 2 to 5 and Examples 1 to 12 were each manufactured in the same manner as in Comparative Example 1, except that the compound shown in Table 2 was used instead of ETL-1 when forming a first electron transport layer, and the compound shown in Table 2 was used instead of ETL-2 when forming a second electron transport layer.

Comparative Example 6

Light-emitting devices were manufactured in the same manner as in Comparative Example 1, except that a first electron transport layer was not formed, and M-2-2 was used instead of ETL-2 when forming a second electron transport layer.

Evaluation Example 1: Measurement of Glass Transition Temperature (T_(g))

While heating each of the following compounds ETL-1, M-1-1, M-1-2, M-1-3, and M-1-4 from 50° C. to 200° C., the glass transition temperature (T_(g)) was measured by analyzing differential scanning calorimetry (DSC). The analysis result of each compound is shown in Table 1 below.

TABLE 1 Material ETL-1 M-1-1 M-1-2 M-1-3 M-1-4 T_(g) (° C.) 102 125 123 120 131

Evaluation Example 1: Evaluation of Driving Characteristics of Device

The driving voltage, color conversion efficiency (efficiency/CIEy), and T97 lifespan of the light-emitting devices manufactured according to Comparative Examples 1 to 6 and Examples 1 to 12 were measured using a Keithley MU 236 and luminance meter PR650, and the results are shown in Table 2. The T97 lifespan is the time it takes to achieve 97% of the initial luminance.

After driving each light-emitting device at 100° C. for 60 hours, the efficiency retention rate compared to the initial efficiency (EA) was calculated according to Equation 1, and is shown in Table 2.

$\begin{matrix} {{{Efficiency}\mspace{14mu}{retention}\mspace{14mu}{{rate}(\%)}} = {\left( {{EB}/{EA}} \right)*100}} & {{Equation}\mspace{14mu} 1} \end{matrix}$

EA is an initial driving efficiency, and EB is the efficiency after driving at 100° C. for 60 hours.

TABLE 2 Color Efficiency First Second Driving conver- T97 retention electron electron volt- sion effi- life- rate (%) transport transport age ciency span @100° C., layer layer (V) (cd/A/y) (h) 60 h Comparative ETL-1 ETL-2 3.72 197 165 61% Example 1 Comparative M-1-1 ETL-2 3.73 195 167 88% Example 2 Comparative ETL-1 M-2-1 3.62 192 209 72% Example 3 Comparative M-1-2 Alq₃ 4.35 87 61 52% Example 4 Comparative M-1-2 M-1-2 3.91 132 93 92% Example 5 Comparative — M-2-2 3.80 156 74 57% Example 6 Example 1 M-1-1 M-2-1 3.61 194 225 100%  Example 2 M-1-1 M-2-2 3.65 192 198 100%  Example 3 M-1-1 M-2-18 3.63 195 189 99% Example 4 M-1-2 M-2-1 3.60 200 212 100%  Example 5 M-1-2 M-2-2 3.62 193 195 98% Example 6 M-1-2 M-2-18 3.63 197 193 100%  Example 7 M-1-3 M-2-1 3.64 190 201 100%  Example 8 M-1-3 M-2-2 3.65 191 183 98% Example 9 M-1-3 M-2-18 3.67 190 190 100%  Example 10 M-1-4 M-2-1 3.63 193 213 98% Example 11 M-1-4 M-2-2 3.62 195 201 98% Example 12 M-1-4 M-2-18 3.63 189 197 98%

Table 2 shows that the light-emitting devices of Examples 1 to 12 have a lower or equivalent level of driving voltage compared to the light-emitting devices of Comparative Examples 1 to 6, and the color conversion efficiency and T97 lifespan are improved. In addition, it can be seen that the light-emitting devices of Examples 1 to 12 have significantly higher efficiency retention rate after driving the device at a high temperature (100° C.) compared to the light-emitting devices of Comparative Examples 1 to 6.

Thus, according to various embodiments, a light-emitting device is capable of having high heat resistance and excellent driving voltage, efficiency, and/or lifetime characteristics.

Although certain embodiments and implementations have been described herein, other embodiments and modifications will be apparent from this description. Accordingly, the inventive concepts are not limited to such embodiments, but rather to the broader scope of the accompanying claims and various obvious modifications and equivalent arrangements as would be apparent to one of ordinary skill in the art. 

What is claimed is:
 1. A light-emitting device comprising: a first electrode; a second electrode facing the first electrode; and an interlayer between the first electrode and the second electrode, the interlayer comprising an emission layer, wherein: the interlayer further comprises a first electron transport layer and a second electron transport layer, the first and second electron transport layers being between the emission layer and the second electrode; the first electron transport layer comprises a first compound represented by Formula 1; and the second electron transport layer comprises a second compound represented by Formula 2, wherein Formula 1 is:

wherein Formula 2 is:

wherein, in Formula 1 and Formula 2: two of X₁₁ to X₁₃ are N, and the remaining one of X₁₁ to X₁₃ is C(R₁₅), X₂₁ to X₂₆ are each independently C(R₂₁) or N, at least one of X₂₁ to X₂₃ and at least one of X₂₄ to X₂₆ is N, CY₁₁ and CY₁₂ are each independently a C₃-C₆₀ carbocyclic group, CY₂₁ is a naphthylene group unsubstituted or substituted with at least one R₂₂ or a fluorenylene group unsubstituted or substituted with at least one R₂₂, L₁₁ to L₁₃, L₂₁, and L₂₂ are each independently a single bond, a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a), or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a), a11 to a13, a21, and a22 are each independently an integer from 1 to 5, Ar₁₁, Ar₁₂, and Ar₂₁ to Ar₂₄ are each independently a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a), b11 and b12 are each independently an integer from 1 to 5, R₁₁ to R₁₅, R₂₁, and R₂₂ are each independently hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group unsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkenyl group unsubstituted or substituted with at least one R_(10a), a C₂-C₆₀ alkynyl group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ alkoxy group unsubstituted or substituted with at least one R_(10a), a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_(10a), a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ aryloxy group unsubstituted or substituted with at least one R_(10a), a C₆-C₆₀ arylthio group unsubstituted or substituted with at least one R_(10a), —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), or —P(═O)(Q₁)(Q₂), c11 is an integer from 1 to 3, c12 is an integer from 1 to 4, two neighboring groups of R₁₁ in the number of c11, two neighboring groups of R₁₂ in the number of c12, R₁₃, R₁₄, or any combination thereof, are optionally linked to each other and form a cyclic group unsubstituted or substituted with at least one R_(10a), R_(10a) is: deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or a nitro group; C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, or a C₁-C₆₀ alkoxy group each, independently, unsubstituted or substituted with at least one of deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂); a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, or a C₆-C₆₀ arylthio group each, independently, unsubstituted or substituted with at least one of deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂); or —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), or —P(═O)(Q₃₁)(Q₃₂), and wherein Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ are each, independently: hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; a C₁-C₆₀ alkyl group; a C₂-C₆₀ alkenyl group; a C₂-C₆₀ alkynyl group; a C₁-C₆₀ alkoxy group; a C₃-C₆₀ carbocyclic group and a C₁-C₆₀ heterocyclic group each, independently, unsubstituted or substituted with at least one of deuterium, —F, a cyano group, a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkoxy group, a phenyl group, or a biphenyl group.
 2. The light-emitting device of claim 1, wherein X₂₁ to X₂₆ in Formula 2 are each N.
 3. The light-emitting device of claim 1, wherein CY₁₁ and CY₁₂ in Formula 1 are each independently a benzene group or a naphthalene group.
 4. The light-emitting device of claim 1, wherein a group represented by

in Formula 1 is a group represented by one of Formulae 1A-1 to 1A-5.

wherein, in Formulae 1A-1 to 1A-5: R_(10aa) and R_(10ab) have, independently, the same meaning as R_(10a) in claim 1; R₁₁ to R₁₄, c11, c12, and R_(10a) have, independently, the same meaning as in claim 1; c12′ is 1 or 2; c13 is an integer from 1 to 4; and * indicates a binding site to a neighboring atom.
 5. The light-emitting device of claim 1, wherein CY₂₁ in Formula 2 is a group represented by one of Formulae 2A-1 to 2A-15:

wherein, in Formulae 2A-1 to 2A-15: Y₂₁ is O or S; R₂₂ has the same meaning as in claim 1; R_(22a), R_(22b), R_(22c), and R_(22d) have, independently, the same meaning as R₂₂; b21 is an integer from 1 to 6; b22 is an integer from 1 to 3; b23 is an integer from 1 to 4; and * and *′ each indicate a binding site to a neighboring atom.
 6. The light-emitting device of claim 1, wherein CY₂₁ in Formula 2 is a group represented by one of Formula 2AA-1 to 2AA-22:

wherein, in Formulae 2AA-1 to 2AA-22: “Ph” refers to a phenyl group; and * and *′ each indicate a binding site to a neighboring atom.
 7. The light-emitting device of claim 1, wherein in Formulae 1 and 2, L₁₁ to L₁₃, L₂₁, and L₂₂ are each independently: a single bond; or a benzene group, a pentalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, or an imidazopyrimidine group each, independently, unsubstituted or substituted with at least one of deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a pentalenyl group, an indenyl group, a naphthalenyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthalenyl group, a fluorenyl group, a spiro-bifluorenyl group, a spiro-benzofluorene-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a carbazolyl group, a benzosilolyl group, a dibenzosilolyl group, a quinolinyl group, an isoquinolinyl group, a benzimidazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), wherein Q₃₁ to Q₃₃ are each, independently, a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group.
 8. The light-emitting device of claim 1, wherein the first compound is a compound represented by Formula 1-1:

wherein, in Formula 1-1, X₁₁ to X₁₃, CY₁₁, CY₁₂, L₁₁, L₁₂, a11 to a13, Ar₁₁, Ar₁₂, b11, b12, R₁₁ to R₁₄, c11, and c12 have, independently, the same meaning as in claim
 1. 9. The light-emitting device of claim 1, wherein, in Formulae 1 and 2, Ar₁₁, Ar₁₂, and Ar₂₁ to Ar₂₄ are each independently: a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a spiro-cyclopentane-fluorenyl group, a spiro-cyclohexane-fluorenyl group, a spiro-fluorene-benzofluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, an indolyl group, an isoindolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, a benzoisothiazolyl group, a benzoxazolyl group, a benzoisoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a thiadiazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, an azacarbazolyl group, a diaza carbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, an azadibenzosilolyl group, an imidazopyridinyl group, or an imidazopyrimidinyl group each, independently, unsubstituted or substituted with at least one of deuterium, —F, —CI, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, C₁-C₂₀ alkyl group substituted with at least one phenyl group, a C₁-C₂₀ alkoxy group, a cyclohexenyl group, a phenyl group, a biphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a spiro-cyclopentane-fluorenyl group, a spiro-cyclohexane-fluorenyl group, a spiro-fluorene-benzofluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, an indolyl group, an isoindolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, a benzoisothiazolyl group, a benzoxazolyl group, a benzoisoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a thiadiazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, an azacarbazolyl group, a diazacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, an azadibenzosilolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), wherein Q₃₁ to Q₃₃ are each, independently, a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group.
 10. The light-emitting device of claim 1, wherein a group represented by

and a group represented by

in Formula 2 are each independently a group represented by one of groups represented by 2B-1 to 2B-20:

wherein, in Formulae 2B-1 to 2B-20, * indicates a binding site to a neighboring atom.
 11. The light-emitting device of claim 1, wherein: the first compound is at least one of Compounds M-1-1 to M-1-30; and the second compound is at least one of Compounds M-2-1 to M-2-19: Compounds M-1-1 to M-1-30:

Compounds M-2-1 to M-2-19:


12. The light-emitting device of claim 1, wherein a glass transition temperature of the first compound is about 110° C. to about 160° C.
 13. The light-emitting device of claim 1, wherein the first electron transport layer is between the emission layer and the second electron transport layer.
 14. The light-emitting device of claim 1, wherein at least one of the first electron transport layer and the second electron transport layer further comprises a metal-containing material.
 15. The light-emitting device of claim 1, wherein: the interlayer further comprises a hole transport region between the first electrode and the emission layer, and an electron transport region between the emission layer and the second electrode; the hole transport region comprises at least one of a hole injection layer, a hole transport layer, an emission auxiliary layer, and an electron blocking layer; and the electron transport region comprises the first electron transport layer and the second electron transport layer, the electron transport region further comprising at least one of a buffer layer, a hole blocking layer, an electron control layer, and an electron injection layer.
 16. The light-emitting device of claim 15, wherein: the hole transport region comprises a hole injection layer and a hole transport layer; and the hole transport layer comprises: a first hole transport layer comprising a first hole transport material; and a second hole transport layer comprising a second hole transport material different from the first hole transport material.
 17. The light-emitting device of claim 1, wherein: the emission layer comprises a host and a dopant; and the dopant comprises at least one of a phosphorescent dopant, a fluorescent dopant, and a delayed fluorescence material.
 18. An electronic apparatus comprising the light-emitting device of claim
 1. 19. The electronic apparatus of claim 18, wherein: the electronic apparatus further comprises a thin-film transistor; and the thin film transistor comprises a source electrode, a drain electrode, and an active layer; and the first electrode of the light-emitting device is electrically connected to the source electrode or the drain electrode of the thin-film transistor.
 20. The electronic apparatus of claim 18, wherein the electronic apparatus further comprises a functional layer, the functional layer comprising at least one of a touch screen layer, a polarizing layer, a color filter, and a color conversion layer. 